Adolescent brain week 1- Nelson
et al (2005)
Nelson et al (2005)- The social reorientation of
adolescence: a neuroscience perspective on the
process and its relation to psychopathology
The three nodes mediating social information processing:
- The early detection and categorization of a stimulus as ‘social’ is followed by
neuronal processing that then integrates the stimulus into a larger emotional and
cognitive framework.
This process involves bi-directional interactions between areas devoted to
social detection and those devoted to affective (limbic regions) and higher
order cognitive processing (prefrontal cortical regions).
- Detection node – categorises a stimulus as social and deciphers its basic properties.
Includes the inferior occipital cortex, inferior temporal cortex regions, intraparietal
sulcus and the fusiform face area.
Superior temporal sulcus seems to be involved in the processing of biological
movement.
Anterior portion of the temporal cortex for social recognition.
- Affective node – composed of regions engaged by reward or punishment such as the
amygdala, ventral striatum, septum, bed nucleus of the stria terminalis,
hypothalamus and sometimes the orbitofrontal cortex.
Stimulus is imbued with emotional significance. Determinations such as
approach/avoid is made.
Modulations of autonomic and cognitive process to organise the systemic
response to social stimulus.
These regions show increased activity during emotionally provocative social
stimuli.
- Cognitive-regulatory node – comprises the medial and dorsal prefrontal frontal
cortex and portions of the ventral prefrontal cortex. 3 basic processes occur here:
1) Perceiving the mental state of others (theory of mind operations). Driven by
activity within the paracingulate area/dorsomedial prefrontal cortex.
2) Inhibition of prepotent responses as regulated by the ventral prefrontal
cortex.
3) Generation of goal directed behaviours. Relies on the interaction between the
dorsal and ventral prefrontal cortices.
Developmental changes in the SIPN during adolescence:
, - Changes that occur in social behaviour during adolescence include the emergence of
sexuality, increase in peer orientation and a decrease in parental and family
orientation.
- Adolescent social re-orientation can be attributed to alterations in processing of
social stimuli within the SIPN that occur as a result of hormones, the maturation of
neuronal processes, and learning.
The detection node:
- Matures quite early in life, well before adolescence with no changes during the
adolescent period.
- Children as young as 3 years are able to reliably distinguish biological from non-
biological motion, and maximum accuracy is achieved on this measure by the age of
5 years.
The affective node:
- These regions are densely innervated by gonadal steroid receptors and undergo
functional and anatomical reorganisation during puberty.
Gonadal steroids alter brain function in many ways such as regulating
neurotraumatic systems including dopamine, serotonin, endogenous opioids,
oxytocin and vasopressin.
It also exerts a strong influence on social processes such as sexual behaviour,
maternal behaviour, social bonding and social memory.
- Gonadal hormones have important effects on how structures within the affective
node respond to social stimuli, and will ultimately influence the emotional and
behavioural responses elicited by a social stimulus during adolescence.
The cognitive-regulation node:
- The importance of the prefrontal cortex in social information processing was seen in
those with damage to this area, since they displayed impairments in social awareness
and decision making.
, Portions of the prefrontal cortex, including orbitofrontal, ventrolateral, and
medial prefrontal regions, do not reach maturity until early adulthood.
- The development that does occur in the cognitive node is a result of increased
myelination and pruning of existing synaptic networks.
In contrast to developmental changes in the affective node, developmental
changes within the cognitive node are likely to be slow, iterative, and
independent of hormonal status.
What can neuroimaging tell us about developmental alterations in the SIPN:
- The surge of gonadal hormones during puberty alters the emotional processing of
social stimuli, as instantiated in the affective as opposed to the detection or
cognitive-regulatory nodes.
- While passively viewing faces with fearful emotional expressions, adolescents
exhibited greater activation than adults in the amygdala, orbitofrontal cortex, and
anterior cingulate.
This finding suggests that when attention is unconstrained, adolescents may
be more sensitive to the emotional properties of a social stimulus.
- However, when we asked subjects to switch their attention between a salient
emotional property of the face and a non-emotional property, we found that adults,
but not adolescents, were able to selectively engage and disengage the orbitofrontal
cortex.
- Several changes take place within the affective node during adolescence such as
perceiving peers as rewarding, and hypersensitivity to acceptance/rejection by peers.
- The ability to take someone else’s perspective first emerges in early childhood and a
region in the dorsomedial cortex is central to this. The region continues to develop
well into late adolescence.
Brain development, SIPN, and affective disorders:
- The incidence of affective and specific anxiety disorders rises dramatically during
adolescence such as depression, panic disorder and social phobia. Changes in the
processing of stimuli within the SIPN can be contributed to this.
Adolescence clearly represents a period of heightened emotional
responsiveness to social stimuli and socially related events.
During adolescence, there is added stress that is placed on the SIPN during a
period of social re-orientation.
There is an apparent mismatch in the development of the affective and
cognitive-regulatory nodes during adolescence.
The functioning of the SIPN during adolescence may provide new insights into
the emergence of gender difference in mood and anxiety disorders.
- Abnormalities in SIPN structures have been reported in adolescents suffering from
mood/anxiety disorders.
Anatomical alterations found in the superior temporal gyrus, ventral
prefrontal cortex, and amygdala of adolescents with a variety of mood and
anxiety disorders.
Alterations in the frontal white matter volume and in choline levels in the
orbitofrontal cortex have been found in depressed adolescents.
Functional abnormalities in amygdala responsiveness to social stimuli has
also been observed in depressed and anxious adolescents.
et al (2005)
Nelson et al (2005)- The social reorientation of
adolescence: a neuroscience perspective on the
process and its relation to psychopathology
The three nodes mediating social information processing:
- The early detection and categorization of a stimulus as ‘social’ is followed by
neuronal processing that then integrates the stimulus into a larger emotional and
cognitive framework.
This process involves bi-directional interactions between areas devoted to
social detection and those devoted to affective (limbic regions) and higher
order cognitive processing (prefrontal cortical regions).
- Detection node – categorises a stimulus as social and deciphers its basic properties.
Includes the inferior occipital cortex, inferior temporal cortex regions, intraparietal
sulcus and the fusiform face area.
Superior temporal sulcus seems to be involved in the processing of biological
movement.
Anterior portion of the temporal cortex for social recognition.
- Affective node – composed of regions engaged by reward or punishment such as the
amygdala, ventral striatum, septum, bed nucleus of the stria terminalis,
hypothalamus and sometimes the orbitofrontal cortex.
Stimulus is imbued with emotional significance. Determinations such as
approach/avoid is made.
Modulations of autonomic and cognitive process to organise the systemic
response to social stimulus.
These regions show increased activity during emotionally provocative social
stimuli.
- Cognitive-regulatory node – comprises the medial and dorsal prefrontal frontal
cortex and portions of the ventral prefrontal cortex. 3 basic processes occur here:
1) Perceiving the mental state of others (theory of mind operations). Driven by
activity within the paracingulate area/dorsomedial prefrontal cortex.
2) Inhibition of prepotent responses as regulated by the ventral prefrontal
cortex.
3) Generation of goal directed behaviours. Relies on the interaction between the
dorsal and ventral prefrontal cortices.
Developmental changes in the SIPN during adolescence:
, - Changes that occur in social behaviour during adolescence include the emergence of
sexuality, increase in peer orientation and a decrease in parental and family
orientation.
- Adolescent social re-orientation can be attributed to alterations in processing of
social stimuli within the SIPN that occur as a result of hormones, the maturation of
neuronal processes, and learning.
The detection node:
- Matures quite early in life, well before adolescence with no changes during the
adolescent period.
- Children as young as 3 years are able to reliably distinguish biological from non-
biological motion, and maximum accuracy is achieved on this measure by the age of
5 years.
The affective node:
- These regions are densely innervated by gonadal steroid receptors and undergo
functional and anatomical reorganisation during puberty.
Gonadal steroids alter brain function in many ways such as regulating
neurotraumatic systems including dopamine, serotonin, endogenous opioids,
oxytocin and vasopressin.
It also exerts a strong influence on social processes such as sexual behaviour,
maternal behaviour, social bonding and social memory.
- Gonadal hormones have important effects on how structures within the affective
node respond to social stimuli, and will ultimately influence the emotional and
behavioural responses elicited by a social stimulus during adolescence.
The cognitive-regulation node:
- The importance of the prefrontal cortex in social information processing was seen in
those with damage to this area, since they displayed impairments in social awareness
and decision making.
, Portions of the prefrontal cortex, including orbitofrontal, ventrolateral, and
medial prefrontal regions, do not reach maturity until early adulthood.
- The development that does occur in the cognitive node is a result of increased
myelination and pruning of existing synaptic networks.
In contrast to developmental changes in the affective node, developmental
changes within the cognitive node are likely to be slow, iterative, and
independent of hormonal status.
What can neuroimaging tell us about developmental alterations in the SIPN:
- The surge of gonadal hormones during puberty alters the emotional processing of
social stimuli, as instantiated in the affective as opposed to the detection or
cognitive-regulatory nodes.
- While passively viewing faces with fearful emotional expressions, adolescents
exhibited greater activation than adults in the amygdala, orbitofrontal cortex, and
anterior cingulate.
This finding suggests that when attention is unconstrained, adolescents may
be more sensitive to the emotional properties of a social stimulus.
- However, when we asked subjects to switch their attention between a salient
emotional property of the face and a non-emotional property, we found that adults,
but not adolescents, were able to selectively engage and disengage the orbitofrontal
cortex.
- Several changes take place within the affective node during adolescence such as
perceiving peers as rewarding, and hypersensitivity to acceptance/rejection by peers.
- The ability to take someone else’s perspective first emerges in early childhood and a
region in the dorsomedial cortex is central to this. The region continues to develop
well into late adolescence.
Brain development, SIPN, and affective disorders:
- The incidence of affective and specific anxiety disorders rises dramatically during
adolescence such as depression, panic disorder and social phobia. Changes in the
processing of stimuli within the SIPN can be contributed to this.
Adolescence clearly represents a period of heightened emotional
responsiveness to social stimuli and socially related events.
During adolescence, there is added stress that is placed on the SIPN during a
period of social re-orientation.
There is an apparent mismatch in the development of the affective and
cognitive-regulatory nodes during adolescence.
The functioning of the SIPN during adolescence may provide new insights into
the emergence of gender difference in mood and anxiety disorders.
- Abnormalities in SIPN structures have been reported in adolescents suffering from
mood/anxiety disorders.
Anatomical alterations found in the superior temporal gyrus, ventral
prefrontal cortex, and amygdala of adolescents with a variety of mood and
anxiety disorders.
Alterations in the frontal white matter volume and in choline levels in the
orbitofrontal cortex have been found in depressed adolescents.
Functional abnormalities in amygdala responsiveness to social stimuli has
also been observed in depressed and anxious adolescents.
