The Infant Crier

Month: April 2020

  • Interoception: Opening Up a New Window to Understand Behavior

    Interoception: Opening Up a New Window to Understand Behavior

    These articles, written by Ira Glovinsky, Ph.D., and Kelly Mahler, MS, OTR/L,  highlight their collaboration applying interoceptive work to infants and young children.

    Understanding interoception, a person’s awareness of internal bodily signals, will have major implications for our work with dysregulated young children. Since the 1940s there has been a continued increase in the number of younger and younger children who are experiencing disruptive behavior disorders and pediatric mood disorders. This presents difficulties in the parent-child relationship both at home and in the child-care setting. Children in pre-K or child- care settings are expelled 3.6 times more frequently than children who are being expelled from grades K-12 altogether (Gilliam, 2005). A new diagnosis in the DSM-5, Disruptive Mood Dysregulation Disorder is now being used to differentiate these children from children who are diagnosed with pediatric bipolar disorder. These are children who are overwhelmed by their emotions in home and school contexts where adults have little or no knowledge how to deal with them. These are children who cannot decode the emotional signals from their bodies and who do not receive these signals until it is too late to do something about it. Becoming attuned and knowledgeable about our interoceptive circuitry as well as learning more about interoception will enable us to do preventive work from the cradle on.

    Interoception: Opening Up a New Window to Understand Behavior

    When I first met Eden, a four-year-old girl, I was immediately drawn to her by the bright gleam in her eyes, her exuberant smile, and her spontaneous, and animated relating ability. Margaret Mahler (1975) referred to this characteristic in her work with very young as “sending power.” This referred to the child’s ability to send non-verbal signals to another person that evokes a return response. Daniel Stern (2010), using different terminology, referred to “vitality affects” as the dynamic energy of a stimulus, “its movement, time, force, space, and intention/directionality” (p.4).

    Eden did everything with forcefulness and energy.

    In interacting with her one had the feeling of being in the presence of a “jazz dancer.” She would react quickly, hit her high point almost instantaneously and remain at her peak level of intensity for a longer period of time than most children or adults. She was spontaneous and animated in her gestures; her body craved excitement and high-level stimulation.

    Eden’s parents, who were more reserved and low-keyed temperamentally, felt that her activity level and intensity were too high, and they were constantly telling her to “calm down!” Nothing they did seemed to work and her most predictable quality was her unpredictability. Her parents were told by family members, neighbors, and friends to work with her on breathing activities such as blowing bubbles or Itzy Bitzy Yoga (Garabedian, 2004) and Itzy Bitzy Yoga for Toddlers (Garabedian, 2008). However, calming activities made her more restless and irritable. Eden was filled with energy; pizzazz, was probably a better word, and she defined what Mahler (1975) described as a child’s “love affair with the world.”

    My first clue to the origin of her behaviors came when Eden burst into my office, loud, irritable, and teary. She exclaimed, “My mommy tells me to calm down! My mommy’s always yelling, ‘Eden calm down, calm down!’. Daddy comes home from work and yells, ‘Eden, calm down! Dr. G., what’s calm mean?” Her uncharacteristic, genuinely confused facial expression, her upset state, and intense body movements struck me.  I took out the book No, David!  (Shannon, 1998) and we began to look at it together. Page by page, she watched David in all sorts of antics that caused his mother to scream at him. By the end of the book she was laughing and exclaimed, “That’s like me!” Looking at her and matching her energy level, I exclaimed “And…that’s…not…calm!” She laughed, but appeared to get the picture without my verbal explanation.

    I began to ask Eden some questions about her awareness of some bodily states. I asked her how she knew she was hungry. She replied, “…don’t know!!” “How do you know when you’re sleepy?” “…don’t know!” When I saw Eden’s parents for a parent guidance session, I asked them about their experiences around eating and bedtime. Her mother responded, “If I didn’t tell Eden to eat, she would go the entire day without eating. Father chimed in and said that bedtime was always difficult because Eden “never got tired. She will just crash at some point!” If it was not for her general joyfulness, I thought that she would easily be a temperamentally “difficult child” (Thomas & Chess, 1968). But she wasn’t, she was fun to be around and very engaging!

    Children like Eden are often seen in the pediatrician’s office, and often referred for “parental exhaustion” syndrome, i.e., the parent who is unable to keep up with the child’s energy level. They are often scooped up into parent-child psychotherapy, sometimes individual therapy, or parent guidance sessions to discuss behavioral management. Strategies that might work for the practitioner’s child are often discussed, books that might work for the author’s child are recommended, but these children really need to be addressed with personalized medicine, a plan that embraces their individual differences and doesn’t come under our current  one size fits all approach. Often, when nothing works, there is a push to medicate — even with a four-year-old — in the hope that the child will be responsive so the practitioner doesn’t have to acknowledge that he or she doesn’t have a clue what to do!

                We are just beginning to learn that there are some children like Eden who truly have no awareness of their inner body states. We give them suggestions about how to deal with anger or frustration although the child does not have any idea what anger and frustration are.

    One young child told me that his therapist told him that anger was like a train that comes down the track. He said that he was told that he should think about anger like a train on an outside track and if you could see the train coming it would have a big light. “When you see the big light coming, take three deep breaths. That’s like anger. When you feel the angry feeling, take three deep breaths.”  The child then said to me, “That guy doesn’t get it!” “What doesn’t he get?” I replied. “I don’t feel anger coming down the track. I don’t feel my anger until the moment before I explode!” Giving such a child recommendations to breathe deeply does not work if the child does not experience the emotion until he is about to explode! Other children have an awareness of many feelings in their bodies but don’t know what they are. “I got lots of feelings!” one child exclaimed. “I don’t have a clue what they are!”

    In working with these children and in a serendipitous experience with Kelly Mahler, a gifted occupational therapist I met for the first time at the STAR Institute- #5 Symposium in Atlanta, Ga.,  (2018) where we both presented on the same day, I became aware of “the eighth sensory system.” We are aware of the five sensory systems: vision, hearing, taste, touch, and smell. Some of us are even aware of the sixth system, proprioception (perception or awareness of the position and movement of the body), and the seventh sense, vestibular (sense of balance), but few of us have heard of the eighth sense, interoception.  Interoception allows us to notice and interpret our bodily signals such as heart rate, muscle tension, skin moisture, bladder distention and so forth.

    Having now interviewed parents, worked with children and adolescents in therapy and seeing some major changes in children who have been seemingly resistant to treatment, focusing on the interoceptive system with families has underscored the importance of working with the body, noticing bodily sensations, linking these sensations to emotions, and then both to actions has enabled many children and adolescents to gain a higher level of control over themselves. The outcome of this work is linked to the foundation or development of reflective functioning. Being aware of what we are experiencing internally helps us form mental pictures and then to think about them, i.e., mentalization and reflection. Interoception is defined as, “the body-to-brain axis of signals originating from the internal body and visceral organs (such as gastrointestinal, respiratory, hormonal, and circulatory systems). It plays a unique role in ensuring homeostasis. Interoception therefore refers to the sensing of the state of the inner body and      its homeostatic needs, to the ever-fluctuating state of the body beneath its sensory (exteroceptive) and musculoskeletal sheath (De Preester & Tsakiris, 2019).

    Children presenting with interoceptive challenges are often misdiagnosed and misunderstood by clinicians and teachers. With the publication of Mahler’s first book, Interoception: The Eighth Sensory System (Mahler, 2015)  her sequel The Interoceptive Curriculum: A Step-By-Step Framework for Developing Mindful Self-Regulation (Mahler, 2019), we now have a tool that specifically describes, explains, and offers a treatment paradigm to put behavioral and mood disturbances under a microscope and address them more systematically and in a way that is understandable to professionals as well as parents and children. Through lessons that focus on noticing sensations in specific parts of the body, then attaching those sensations to emotions and then to actions, parents are reporting changes in children’s understanding of how their bodies actually feel because they develop the ability to notice and describe a wide variety of body-emotion connections.

    Connecting body sensations to emotions is a major milestone for children, adolescents, and adults. As adults, we frequently tell a child how he or she is feeling because we attend to facial expressions and body movements that evoke feelings in us. The problem is that the feelings that are evoked in us may have nothing to do with the feeling that the child is experiencing in the moment. In fact, our words can easily confuse a child who is feeling one emotion but being told by an adult that it is a different feeling. When we play with a child’s reality by giving the child a different reality, we are adding to their confusion about emotions. We are now beginning to understand that facial expressions may not reveal an individual’s emotions unless we totally understand the context. In the book How Emotions Are Made (Feldman-Barrett, 2018), there is a picture of a woman with her fists clenched and looking like she has been terrorized.  Most people looking at the picture would think that this woman is overwhelmed, negatively. But when the total context is then presented, it is revealed that the woman is Serena Williams expressing her elation at winning Wimbledon!

                Putting all of the pieces together, understanding interoception, and seeing how emotions are constructed in moment-to-moment experiences is opening up the door to meaningful and successful interventions.

    The therapeutic work that has been done on the body has been done primarily with adults. However, this type of work is most applicable to children who have a smaller “language toolbox” and are just learning about emotions. Children express their emotions through their bodies and through their actions before they develop an emotional vocabulary. Starting with interoception, using a paradigm of body-emotions-actions (Mahler, 2019) promotes meaningful transactions between children, parents, and professionals. It facilitates attunement, synchrony, and contingency with very young children, enabling us to join them in their worlds and to develop a higher level of understanding into the behaviors that we see in front of us, but have difficulty interpreting.

    References

    Barrett, L.F. (2018) How Emotions Are Made, New York: Mariner Books.

    Garabedian, H (2008) Itsy Bitsy Yoga for Toddlers. Cambridge, Mass.: Da Capo Press

    Garabedian, H. (2004) Itsy Bitsy Yoga. New York: Atria Books

    Mahler, K. (2015) Interoception: The Eighth Sensory System. Lenexa, Kansas: AAPC Publishing.

    Mahler, K. (2019) The Interoception Curriculum. kelly-mahler.com

    Mahler, M. (1975) The Psychological Birth of the Human Infant. New York: Basic Books

    Shannon, D. (1998) No, David. New York:  Blue Sky Press.

    Stern, D. (2010) Forms of Vitality: Exploring Dynamic Experience. Oxford, UK: Oxford University Press.

    Thomas, A. & Chess, S. (1968) Temperament and Behavior Disorders in Children, New York: New York University Press.

  • Sarah

    Sarah

    Sarah was an angelic-looking, bright-eyed four-year-old girl. She had a gleaming smile, immediate approaching behavior, and exuberance, but she was exhausting to manage at home and in her preschool setting. Her parents contacted me because of her aggressive behavior and inability to control her impulses, her refusal to follow instructions and directions, and her lack of awareness of her physical strength. Sarah gave hugs like a “Mama Bear.” One of the first things that her mother said to me was, “She just doesn’t know how to be gentle! She’s like a bull in a china shop!”

    They sought treatment so they can help her adapt to situations better and to get along with other children better. Her mother would like help because she feels worn down!

    Historically, Sarah was a full-term infant weighing almost eight pounds and obtaining APGAR scores of 9 and 10 at one and five minutes respectively. During her first year the major problem was her recurrent ear infections; she was given ear tubes when she was two.  Sarah was breast-fed for about eight months, and her mother recalled that her sucking response was like a vacuum cleaner! She had a “voracious” appetite. Her sleep pattern was not unusual, but when she awakened, even as an infant, she was active, alert, intense, and wearing on her mother. Mother described her husband as “a saint! He was and is the only one who can keep up with her!”

    Sarah met developmental milestones on time; she began to present symptoms when she was about 2½. She had difficulty going along with family routines, was irritable, and very restless. She would get overly excited and was very difficult to calm down. Mother recalled that she was very sensitive to touch and would startle when she was touched. She began to display temper tantrums. Her over-excitability, restlessness, and tantrums have continued. She was described as one of the kids who goes from zero-to-sixty instantaneously. She had difficulty falling asleep and remaining asleep since she was about two. She never seemed to feel sleepy.

    Sarah’s family included her eight-year-old and six-month-old sisters. Her parents, married 12 years, met in high school. They described their marital relationship as positive for both. They shared the childcare and they were both supportive of each other. Sarah’s mother was 35 years of age, her father 39. Both parents had college degrees and worked in the medical field. Sarah attended nursery school five days a week and was then cared for by a nanny — who had been consistent in her life — until her parents came home between five and six o’clock.

    Mother stated that Sarah loved active, gross motor activities and had started a gymnastics class in which she was apparently doing well with the exception of having to be “corralled” to keep her in one place when she gets excited. She participated in all activities, but then want more and more when it is time to stop. She had boundless energy! Father commented on the fact that Sarah didn’t have an awareness of where her body stops and the next person’s body begins. She would run into people or objects and not feel pain, but when someone touched her, she over-reacted. Sarah also has displayed an interest in art and music and loves animals.

    On an attention questionnaire, her parents indicated that she loses focus unless she is very interested in an activity. Her days are either excellent or poor with little “in-betweens.” She generally has difficulty finishing something that she starts. Her attention is variable as she “tunes in” and “tunes out.” Often, her attention is hard to attract and her work in school has an unpredictable quality. She can enjoy an activity one day and then the very next day she will reject the same activity.

    Sarah was easily distracted by sounds and her parents felt that she did not attend to signals so she missed important information. She also was easily distracted by visual stimuli She craved excitement. Both parents agreed that she didn’t  think before she acted; she did the first thing that came to her mind, and she did too many things too quickly. She had difficulty making friends and she tended to spend a lot of time by herself. Punishment did not seem to affect her and she made the same mistakes over and over again. Talking to her about her behavior had no effect in changing her. In school she seemed to treat other kids like they are objects, bumping into them and pushing them out of the way.

    Sarah and her parents have been healthy,  and there are no significant medical, mental health, or learning problems in her parents or extended family members.

    According to the initial assessment process, several concerns presented by Sarah’s parents indicated that interoceptive awareness, or awareness of internal bodily signals, could be an area of challenge and warranted further investigation. Some of these reported concerns included:

     

    Reported Concern Possible relation to interoceptive awareness
    Sarah would get overly excited and had difficulty calming down. This could indicate that Sarah was unaware of her bodily and emotional responses, thus leading to an inability to self-regulate (the ability to notice how one feels precedes the ability to manage the feelings).
    Sarah was very sensitive to touch. Startled when she was touched.

     

    		 Many of the skin fibers traditionally thought to be part of the tactile system are now found to be part of the interoceptive system. Interoception influences the experience of social and pleasurable touch.
    Sarah has a high pain tolerance. She will run into people and not feel pain.

     

    		 Pain signals are processed by the interoceptive system; therefore this atypical pain experience may reflect an interoception issue.
    Sarah doesn’t know her own strength (giving bear hugs). She doesn’t know how to be gentle. She’s like a bull in a china shop. She has a lack of boundaries and does not seem to know where her body ends. This could indicate a global poor body awareness, which is a skill influenced by the interoceptive sense.

     
    Sarah does not seem to know when she is emotionally overloaded.

     

    		 Poor emotional awareness or understanding is a hallmark sign of poor interoception function. Interoceptive awareness provides the foundation of the emotional experience. The ability to notice and connect body signals to the meaning is what allows us to clearly identify what emotion we are experiencing.
    Sarah is exhausting to manage at home. She still has a strong need for external controls.

     

    		 This could indicate a lack of internal control caused by confusion or poor awareness of internal bodily (interoceptive) sensations.

    Intervention:

    Due to the possible interoception challenges affecting Sarah’s ability to successfully self-regulate, incorporating interoception into the therapy process was deemed appropriate. The Interoception Curriculum: A Step-by-Step Framework for Developing Mindful Self-Regulation (Mahler, 2019) provided the guide for implementation of this work.

    To start, the work focused on Sarah’s ability to notice body signals or to become more aware of her internal bodily experience.

    As outlined in Section 1 of the curriculum, each week Sarah focused on one body part, spending time engaging in fun activities designed to evoke sensations within that one body part, giving her practice noticing and describing the way that body part felt. For example, during the first session (week 1), Sarah, along with the parent in attendance, focused on the hands and explored all of the different ways their hands could feel using concrete Focus Area Experiments (e.g., putting hands in cool water, touching an ice cube, squeezing a ball, holding a handwarmer, blowing on the back of the hand, etc.).

    During the week, outside of the session, Sarah practiced noticing the way her hands felt during daily activities. She did this in two ways: Her parents would use IA on the Fly, which is a strategy where they used specific verbal prompts to ask Sarah how her hands were feeling. Sarah also practiced noticing body signals by completing Body Checks with her parents. This strategy uses a visual support that contains a body outline as well as body part icons that contain descriptor words she could use to describe the way each body part felt (see Picture 1). Sarah would complete the Body Check verbally with her mom or dad guiding her through noticing how her hands were feeling in that moment. Sarah’s parents also began completing their own Body Checks along with Sarah so that it became a structured activity that facilitated greater attachment and attunement.

    Picture 1: Sarah’s Body Check Chart.

    Sarah and her parents moved through this same process over the next few sessions (completing Focus Area Experiments during the session and Body Checks for positive practice during daily activities outside of the session), focusing on a different body part each week. The order of body parts, as listed in Table 2, moved from more concrete outer body parts to more abstract inside body parts. By the time she completed this process for eight out of 15 body parts included in the curriculum, Sarah was able to independently identify how each body part felt in the moment, using a wide range of age-appropriate descriptor language (due to her age, it was determined to focus on eight main body parts and her parents could use the same process to work on noticing body signals in more advanced body parts as Sarah matured).

    Week # Body Part of Focus
    Week 1 Hands
    Week 2 Feet
    Week 3 Mouth
    Week 4 Eyes
    Week 5 Ears
    Week 6 Skin
    Week 7 Muscles
    Week 8 Lungs

    As Sarah and her parents participated in the lessons from Section 2 of the curriculum, they practiced connecting body signals to a variety of emotions. For example, Sarah discovered that when her muscles felt “jumpy,” that was a clue that she was really excited.  Or when her mouth felt “dry,” that was a sign that she was thirsty. At home, parents were taught to use IA on the Fly (verbal prompts) to guide Sarah in connecting the body signals she noticed to the emotion (e.g., “Sarah, you said your eyes feel heavy. That is a great clue! What emotion could it mean?”) Wrapping up the curriculum with Section 3, Sarah was guided in discovering feel-good actions that helped her body feel comfortable.

    Clinical reasoning behind The Interoception Curriculum

    The Interoception Curriculum allowed Sarah to playfully gain understanding and control over body feelings via a systematic process. The work was thoughtfully chunked into small sections to make it manageable and not overwhelming (e.g., focusing on noticing body signals in one body part at a time). The process was predictable, which made it feel familiar and safe for Sarah and doable for her parents to incorporate into a busy family routine. Parents were involved in every step of the process, and focus was on empowering them to be able to support Sarah in developing clear body-emotion connections.

    Therapy often focuses on regulation or coping strategies and fails to account for the underlying mechanism (interoception) that serves as the alert to use the strategies.

    The process used with Sarah targeted the ability to notice and connect body signals, which served as her motivation to self-regulate.

    Due to this focus, Sarah gained a sense of control over her body feelings and became a notably more confident and regulated child.

    Implications for Infant and Early Childhood Mental Health

    Interoception is intimately tied to the infant population, and the implications for infant mental health interventions are enormous. Infants do not have the language to articulate their inner experience, but they do have the “body language” to express themselves, e.g., crying, prolonged irritability, and moodiness. As the infant matures and develops language, if we ask the right questions, we can become attuned to the child’s experience. In our clinical work if we begin to ask: “How do you know you’re angry?” rather than “Why are you angry?” we may get a shrug or the response “I don’t know,” and find out that the child is not receiving the interoceptive signals of anger.

    A young child with whom I worked stated, “I don’t feel anger until the moment before I explode.” All the mindfulness work that was attempted to help him calm down before he got too angry went nowhere because he was not receiving the signals. Other children tell us that they have lots of feelings, but they don’t know what they are because their interoceptive systems are not working efficiently and they cannot differentiate the signals. Interoceptive signals help us differentiate self from other, enabling the young child to recognize that feelings in an interaction belong to oneself or to the other.

    Interoception is a critical variable in infant-parent psychotherapy and brings a new dimension into our clinical work. The concept of interoception is essential in parent and professional training. Our experiences as infants become embodied and can affect our psychological development years later. I had firsthand experience with a young adult who had had a very serious urinary surgery when she was 18 months old. She came into therapy in her early 20s suffering from agoraphobia. She slowly made her own associations to the experiences of being taken away from her parents in the hospital, experiencing what felt like assault by doctors, being placed in a bare room in a crib with slats that confined her and experiencing an intensity of lighting that, as an adult, was similar to the lights in a friend’s house where she couldn’t get herself to sleep. As she became re-connected to these late infancy experiences and made her own connection to these experiences, she made major gains in therapy. She was able to do things for which she had been paralyzed until she began to understand these connections.

          If we help children get acquainted with their bodies from the beginning by helping them learn about sensations in each of their body parts, they begin to develop a sensations vocabulary and can tie these sensations together to develop an emotions vocabulary.

    As children develop this awareness, with caregiver support they develop actions or strategies to deal with what they are experiencing. This has the possibility to decrease the number of children who develop early mood and disruptive behavior disorders. If we know what we are feeling and where we are feeling it, we can prevent and intervene to decrease arousal and help very young children develop neurophysiological modulation, sensorimotor modulation, control, self-control, and then self-regulation (Kopp, 1982). Our understanding of individual differences among children and the patterns of arousal in each individual child will enable us to develop the prevention and intervention tools that are currently limited at home, in school, and in clinical settings. This work is clearly cutting edge, and we still have a great deal to learn about it.

    For further reading:

    Craig, A.D. (2009) How do you feel-now? The anterior insula and human awareness. Nature Review Neuroscience, 10, 59-70.

    Critchley, H.D., Wiens, S., Rotshtein, P., Ohman, A., Dolan, R.J. (2004) Neural systems supporting interoceptive awareness. Nature Neuroscience, 7, 189-195.

    Damasio, A. R. Descartes’ Error: Emotion, Reason, and the Human Brain. New York: Picador.

    Gilliam, Walter. “Pre–K Students Expelled at More Than Three Times the Rate of K–12 Students.” Yale News, 12 Sept. 2011, news.yale.edu/2005/05/17/pre-k-students-expelled-more-three-times-rate-k-12-students-0.

    Fotopoulou, A. & Tsakiris, A. & Tsakiris, M (2017) Mentalizing homeostasis: The social origins of interoceptive inference. Neuropsychoanalysis, 19 (1), 3-28.

    Kopp, C. (1982) The antecedents of self-regulation: A developmental perspective, Developmental Psychology,18 (2), 199-214.

    Mahler, K.  (2019) The Interoception Curriculum: A Step-by-Step Framework for Developing Mindful Self-Regulation

    Oestergaard Hagelquist, J. (2015) The Mentalization Handbook London, UK: Karnac

    Thompson, R. (1988) Emotion and self-regulation. In Thompson, R. (1988) Socioemotional Development, Lincoln, Neb.: University of Nebraska Press.

    Van der Kolk, B. (2015) The Body Keeps the Score. London, UK: Penguin Books.

  • Interoception and Infant Mental Health: An Exquisite Fit

    Interoception and Infant Mental Health: An Exquisite Fit

    Interoception as a Foundation of Infant Mental health     

    We see interoception as a foundational concept for infant mental health. Our early development of a sense of self is an “embodied” sense of self that occurs prior to the development of a “mindful” sense of self. There has been an ongoing debate since the time of Freud regarding the origin of the self. Is the origin of the self related to the body and the sensory system or is the origin of the self related to social interactions?  Recently, Fotopoulou & Tsdakiris (2017) proposed that “building a mind, and understanding other minds, are embodied and tightly connected processes.” We argue that the constitution of the self is dependent upon the social mentalization of the body and particularly its homeostatic needs. In short, the radical aspect of our proposal is that social interactions do not shape only the reflective (narrative or extended) self and related notions of affect regulation and social cognition. Instead, the most minimal aspects of selfhood, namely the feeling of being an embodied agentive subject are fundamentally shaped by embodied interactions with other people in early infancy and beyond. Progressively these embodied interactions allow the developing organism to mentalize its homeostasis and hence they constitute the core of our objective subjectivity.

    Sensory Systems are Developing in Utero

    How might these systems be linked in infancy and what are the implications? First, our sensory systems are developing in utero so that sensory input is being processed even before the infant is born.

     The development of the tactile system

    The tactile system is the first system to develop in utero and is the most mature system at birth. By the fifth gestational week, the embryo is able to sense pressure in the lips as well as the nose. By nine weeks gestation pressure is also sensed in the fetal arms, chin, and eyelids, and by 10 weeks the fetus is experiencing sense pressure in the legs. By 14 weeks, a healthy fetus can sense pressure in most of the body. In the fetus’ third trimester the touch sensors in the fetal skin are becoming wired into the insular cortex of the brain where the fetus can respond to the contextual features of touch (Weinstein, 2016, p. 128). Tactile awareness in the back and top of the head does not develop until the infant is born and this may enable the infant to weather the experience of labor and birth (Weinstein, 2016, p. 128). Touch is a primary sense for attachment formation.

    The development of sight

    The optic primordium cells that are necessary for the development of vision begin to form at about 28 days of gestation and, at approximately two months’ gestation, there are axon connections that form as the eyes grow and move from behind the cranium to their front positions. Between 14 and 28 weeks gestation there are about 100 million neurons that have formed but are not yet connected. The infant can see light through the mother’s belly and amniotic fluid by the last trimester (Weinstein, 2016, p.127).

    The development of taste

    By eight weeks gestation there are taste buds on the tongue. These buds are further formed around the mouth at 13 weeks. The fetus is able to taste amniotic fluid by four months gestation (Weinstein, 2016, p. 127).

    The development of smell

    By eight weeks gestation the fetal olfactory sense is near full maturation and by the end of the first trimester the main olfactory subsystem is a functioning sensory system. Smell receptors are functioning by 10 weeks gestation. Thus, the fetal olfactory system is working before the child is born. The smell of amniotic fluid, which is similar to the scent of breastmilk is already beginning to become familiar to the fetus.

    Auditory system

    Three-and-a-half weeks after fertilization the ears are beginning to differentiate (Weinstein, 2016, p. 126). The fetus is able to hear by the end of the middle of the second trimester (Weinstein, 2016, p. 126). Auditory information can be carried from the ear to the brain by four to five months gestation when the eighth cranial nerve is developed.  Weinstein (2016) notes that the most consistent sounds and rhythms that the fetus is hearing are the mother’s heartbeat as well as her voice. She also adds that the fetus (prenate) can respond to sound as well as indicate sound preferences by 23 weeks gestation and three weeks later is learning intonation, rhythm and other maternal speech patterns. By 34 weeks the fetal auditory threshold levels are comparable to adult preferences (Weinstein, 2016, p. 127).

    The development of the proprioceptive and vestibular systems

    Beyond the more well-known five senses, the proprioceptive and vestibular systems — ; sixth and seventh respectively — also play important roles in an infant and young child’s development The proprioceptive system functions and enables the infant to feel a sense of location as well as the position of different parts of the body in space and in relation to other animate and inanimate objects. It also enables the infant to have an inner awareness of body posture (Williamson & Anzalone, 2001). Williamson & Anzalone (2001) state that proprioception gives us information about the body’s orientation in space as well as the relation of other body parts to each other, the rate and timing of our movements as we move, the force that our muscles exert, how fast and much our muscles are lengthened or shortened when we engage in activities, and the angles at which each of our joints change as we move. Because the fetus moves in utero, the proprioceptive receptors enable the fetus to practice movements even before the infant is born. (Weinstein, 2016, p. 129). Our proprioceptive sense enables us to develop a schema of our body, i.e., a physical sense of self, an inner awareness of our body parts and how they relate to our larger body systems, and how these parts move through space (Williamson & Anzalone, 2001, p. 9-10).

    The vestibular system that is in the bony labyrinth of the skull is also attached to our hearing mechanism. This system is comprised of three structures in our inner ears: the semicircular canals, the saccule, and the utricle. The semicircular canals enable us to register the speed, force, and direction as we turn our heads when we look around or when we swing. The functions of the vestibular system include the regulation of our muscle tone and coordination, our balance and equilibrium, the control of our eye movements so that we can maintain a stable visual field when we move, our maintaining and transitioning of our states of arousal, and our levels of attention (Williamson & Anzalone, 2001, p.8). Vestibular functioning that helps the body’s response to head movement and gravity is functioning early in gestation (Weinstein, 2016, p. 12-129).

    What goes on even before an infant is born can impact the architecture and development of the fetus, programming the fetus to the kind of stimulation that will be experienced after birth.

    Thus, a calm fetal environment prepares the fetus to engage with a calm postnatal environment. A stressful prenatal environment prepares the fetus to deal with similar stimulation after birth. If the external environment that is experienced after birth is different from the environment that the fetus has experienced in utero, the infant will not be prepared for that environment and this has important consequences for the infant’s interoceptive development and adaptation.

    When the baby is born, he or she is placed on the mother’s abdomen and both partners experience body-to-body contact. The mother’s interoceptive system is fully functioning and the experience of the baby’s body on her resonates throughout her system. The experience is on a positive-negative continuum as well as on a high-low arousal intensity. The baby is experiencing visceral stimulation of warmth or coolness, softness or rigidity of the mother’s body, the sounds, intensity of light of the neonatal context. Over time the infant begins to form the seeds of his or her internal working model of the world. These experiences energize the interoceptive systems of both partners and are the earliest components in the development of attachment. When things go right for both the mother and the baby, the roots of a secure attachment begin to be experienced. However, when things do not go well, the stress system for both partners becomes activated. Such experiences may form the earliest foundation and predisposition of mood disturbances. This is an area for further study.

    When the Hypothalamic-Pituitary-Adrenal (HPA) system is activated there is an increase of cortisol and the amount of blood that is pumped by the heart increases and the release of epinephrine cause the contractions of the heart muscles to increase. This is an interoceptive signal. When the HPA system in the infant begins to function, the release of these chemicals affect the developing emotional system of the child and most likely impinge on the development of the attachment and social systems. There is not yet data in infants to map the development of the interoceptive system, but we do have the tools to assess changes in the stress and attachment .

    Research into the interoceptive system, stress system, and attachment system is imperative. If an infant or toddler has certain experiences or doesn’t have certain experiences, often the outcomes seem inevitable. More continues to be discovered about neurological and systems plasticity every day. Due to these growing discoveries, infant and early childhood professionals need to be proactive but cautious, and evaluations should be longitudinal rather than static and interdisciplinary and collaborative.

    Implications for infant mental health

    Infant mental health intervention is dyadic intervention; the port of entry is the infant-parent system. The infant affects the family system as the family system affects the infant. This has major implications for intervention. This fits in with interoceptive difficulties as well. In treating infants, toddlers, and preschoolers it is necessary to work with the parent-child system rather than with the infant, toddler, or preschooler alone.

    The development of self-regulation is a primary outcome of interoceptive treatment, and this cannot occur unless the parent and infant, toddler, or preschooler are treated together.

    Self-regulation is the foundation of mental health adjustment for all of us. If we are not able to modulate our neurophysiology, modulate our sensory systems, or develop control, self-control, and self-regulation we cannot function efficiently within any environment. Engagement, back-and-forth interactions, contingency, sharing, ideas, and eventually healthy reality sense, reality testing, and reality adaptation are dependent upon self-regulation. It starts from the outside (caregiver) being the external regulator,  while the caregiver’s regulatory techniques scaffold the child’s self-regulation skills.

    The caregiver acts as a social biofeedback machine in which the infant learns about their internal signals and emotions through the caregiver’s feedback and response to their expressive cues (Buck, 1989). For example, at birth, initially the sensation of hunger is simply a vague, unpleasant feeling and the infant learns through interactions with the caregiver about the meaning and motivational value of the internal sensation of hunger (Harshaw, 2008). Taken together, the infant-caregiver relationship potentially influences the infant’s ability to:

    1. Notice internal body signals: The infant recognizes body signals as important constructs that are validated and tended to consistently by the caregiver
    2. Connect the body signals to the emotion: The infant begins to accurately interpret body signals through the feedback provided by the caregiver
    3. Regulate by using a feel-good action: The infant learns to self-regulate through the observation of the strategies used by the caregiver to co-regulate

    Future Considerations

    To date, the interoceptive literature has been primarily anatomical and theoretical. Kelly Mahler is a pioneer in intervention with children. Her model fits exquisitely with the infant mental health model of treatment. Presently, her curriculum is used primarily with three-year-olds  and up, but with modifications it can be used with children as young as two. Working with children involves developing a vocabulary of sensations, and then an emotional vocabulary, before developing action strategies. These vocabularies stretch the range of words for sensations and emotions. The work of Lisa Feldman Barrett has shown that our emotional vocabularies tend to be limited and we do not spend time teaching children to differentiate gradients of sensations and emotions. Thus, by working with the dyad, both parent and child are learning about the different interoceptive experiences as well as the gradient of intensities that contribute to our individual differences.

    By developing tools and techniques to help infants and toddlers to become maximally aware of their bodies and their interoceptive signals, there is more opportunity for doing preventive interventions. This will broaden the field of infant mental health intervention services. As more research is done on the development of interoception from infancy onward, the melding of interoception with infant mental health will be a powerful combination for treatment. This series of articles provides a beginning for researchers and practitioners to include the literature on interoception as a central foundation concept in infant mental health training programs.

    Buck R. Emotional communication in personal relationships: A developmental-interactionist view. In: Hendrick C, editor. Close relationships. Newbury Park, CA: Sage; 1989. pp. 144–163.

    Bruch H. Hunger and Instinct. Journal of Nervous and Mental Disease. 1969;149:91–114.

    Harshaw, C. (2008). Alimentary epigenetics: A developmental psychobiological systems view of the perception of hunger, thirst and satiety. Developmental Review, 28(4), 541-569.

    Oldroyd, K., Pasupathi, M., & Wainryb, C. (2019). Social Antecedents to the Development of Interoception: Attachment Related Processes Are Associated With Interoception. Frontiers in psychology, 10.