Brain/Behaviour relationship Flashcards
Cranial Nerves
Sensory and Motor
Sensory - take info from external environment into brain (olfactory, optic, auditory, vestibular)
Motor - Movement (Spinal, hypoglossal, oculomotor, trochlear, abducens, facial)
Functions Hindbrain and Brainstem
Medulla Oblongata and Pons
Regulates basic functions such as heart rate, respiration, blood pressure, swallowing, eye movement
Functions Hindbrain and Brainstem
Reticular Formation
arousal & sleep/wake cycle
Functions Hindbrain and Brainstem
Cerebellum
Balance & coordination and learning of skill movements, muscle tone, cognitive and motor sequencing (esp. timing)
Function Midbrain
Tectum
Superior colliculi (nuclei for visual function) Inferior colliculi (nuclei for auditory function) - orienting
Function Midbrain
Tegmentum
eye movement
Function Midbrain
Ventral Tegmental Area
natural reward circuitry (motivation, social affiliation) Dopamine producing (Alongside nucleus accumbens)
Diencephalon
Thalamus
Relay station for sensory signals – lateral (visual), medial (auditory) geniculate nuclei, dorsal (memory) and ventral posterior nuclei (sensory)
Diencephalon
Hypothalamus
Regulates hormone release from the pituitary gland Mediates ANS function and behaviour - Fight or flight - Hunger/thirst - Sexual drive
Limbic System
Emotion, memory & learning, motivation – fleeing/ fighting, feeding and sexual behaviour
Contains Hypothalamus, Mammillary bodies, Cingulate gyrus, Hippocampus, amydala
Amydala
Primary processing of emotion
Hippocampus
Memory
Basal Ganglia
Contain the caudate nucleus, globus palladis, putamen, limbic (nucleus accumbens and ventral tegmental area)
Important for voluntary control of motor function, procedural and reward learning, executive functions, emotion
Dysfunction of Basal Ganglia
Parkinsons - Tremours at rest, rigidity
huntington - whole body twisting, violent movement
Cerebral Cortex Lobes
Frontal Lobes
motor, executive function, behavioural regulation, memory, speech production
Dorsolateral - memory and attentional processing
Medial - judgement, decision making and detection errors
Frontal - planning, guidance, evaluation of behaviour
Damage = lower performance on IQ testing, problems with organising.sequencing behaviour, modulating behaviour, initiating/cessating behaviour, generating appropriate emotional responses, using strategies to retrieve memories (repeat activities and find hard to initiate new activities)
Cerebral Cortex Lobes
Temporal Lobes
audition, speech comprehension, emotion, memory, visual perception, processing music
Hippocampus - consolidation long term memories
left = verbal right = spatial info
Damage = prosopagnosia, inability recognise common sounds, agnosia (auditory and visual)
Cerebral Cortex Lobes
Parietal Lobes
somatosensory, visual perception, multi-modal integration of stimuli
Integrating information from sensory modalities, sensory info into stored memory and internal state to external environment
Somatosensory processing:
- Primary area: recognition of sensory stimuli from contralateral side of the body
- Secondary area: tactile perception, touch discrimination and body sense
- Tertiary area (TPJ): integration of stimuli (visual, auditory and somatosensory); guiding movement in space and spatial representation
damage = alexia, agraphia (problems reading and writing, apraxia (inability to perform skilled movement), spatial processing (locating sound in space) Heminegelct- neglect left visual field
Cerebral Cortex Lobes
Occipatal Lobes
vision
Cerebral Cortex Lobes
Insula
consciousness, interoceptive awareness, self-awareness, emotion (contagion), body homeostasis, pain (Describe pain)
Develop during adolescence (Self identity)
Overactive for people with depression (internal focus, rumination)
Compassion for self and others
What are the 2 visual pathways
Temporal lobe- Ventral Stream - detect what visual info is (What? - Stimulus recognition)
Parietal Lobe - Dorsal stream - locating object in space (Where? - Guiding visual movement)
What are the consequences of damage to the Temporal visual areas?
Visual agnosia: inability to combine visual impression into complete patterns and interpret these
Object agnosia:
- Apperceptive: Inability to develop a “percept” of objects (failure to recognise objects, cannot copy, cannot match)
- Associative (failure to recognise objects despite intact perception – can copy/match objects but not identify) – failure to associate visual representation with meaning
Prosopagnosia:
inability to recognise faces
Bilateral damage to the occipital-temporal junction (fusiform)
What are the consequences of damage to the parietal visual areas?
Right: contralateral neglect, inability to consciously attend to objects in the left visual space despite intact visual pathways and cortex (spatial attentional problem)
Left/bilateral – multimodal integration (temporo-parietal junction) = visual/auditory/tactile & motor
Affects reading, writing, maths and skilled movements (alexia/dyslexia, agraphia, acalculia, apraxia)
What occurs when occipital lobe is damaged?
Area 17: Contralateral loss of visual sensation and recognition
Areas 18, 19: Perceptual problem: difficulties in discriminating visual objects that are different in sizes, shapes, orientations, and colours
Types tactile processing disorders
Primary and secondary
Primary area (somatosensory strip)
- Loss or alteration of sensation of touch, pain, temperature and body sense on contralateral side of the body
Secondary area
- Partial or complete inability to recognise somatosensory stimuli. 2 types:
- Loss of ability to recognise objects by touch
- Loss of knowledge or sensory awareness of one’s own body or bodily condition
Hierarchy of motor movement and brain areas involved
Tertiary - Formation of behavioural intention (prefrontal cortex)
Secondary - Preparation and organisation of motor programmes (Premotor areas of frontal lobe)
Primary - execution of motor programmes (Motor cortex and input form the thalamus and basal ganglia, to spinal cord)
Damage to motor areas
Damage to primary motor area: impairment of motor functioning (speed, movement and strengths) in limb and digits – extensive damage = hemiplegia
Damage to tertiary and secondary motor areas: impaired planning, selection and organisation of motor behaviour – apraxia and apathy
Damage to auditory processing areas
Primary, secondary and tertiary
Damage to primary, secondary and tertiary areas (41, 42, 22) of temporal lobe can lead to disorders of auditory sensation and perception
damage to primary area of auditory cortex - deficits in discrimination
damage to secondary and tertiary areas = Auditory perceptual problems
Auditory agnosia (amusia, agnosia for sounds)
Left hemisphere - Speech
Right hemisphere - Music
Damage to language areas
Wernicke’s aphasia (Left hemisphere)
- deficits in language comprehension, word recognition, poor repetition
Broca’s aphasia (Right hemisphere)
- problem with speech production
Global Aphasia - non-fluent spontaneous speech, poor comprehension, poor repetition and naming
Conduction Aphasia - Fluent spontaneous speech, good comprehension, poor repetition and poor naming, tend to repeat what someone has said
Where do verbal hallucinations originate?
activated the primary auditory cortex, Broca’s area, and speech zone in posterior temporal cortex (LH), and limbic system
Attention systems
Posner model of attention (3)
1) Alerting or Arousal Network (security guard – surveillance and alert) – brain stem (RAS) and parietal lobes – sustained attention or vigilance
2) Orienting Network (signal detection - brain shifts from general to specific attention) – selective attention (midbrain, parietal and Temporoparietal Junction)
3) Executive Network (signals are evaluated and a decision is made about what to do next) – Dorsolateral PFC and ACC, attentional switching and divided attention
Areas of brain for each type of memory
Declarative (Episodic - Memory of past events - and semantic - facts about the self and the world)
- Medial temporal lobe, diencephalon
Nondeclarative memory
- Procedural (Skills, Habits) - Basal Ganglia
- Priming - Neocortex
- Simple classical conditioning - amygdala, cerebellum
- Habituation/sensitization - Reflex pathways
Damage to temporal lobes (Memory related)
Damage to medial temporal cortex (hippocampus) leads to material specific memory problems
LH problem in learning and remembering verbal material
RH problem in learning and remembering visual material
Role of the Amygdala
Role in emotional processing and emotional learning and memory (both implicit/explicit).
Mediates approach and withdrawal behaviour
Fear conditioning – neutral stimuli gets paired with fearful experience and produces fear reaction (phobia and avoidance reactions)
interacts with the hippocampal memory system:
- Responsible for assigning emotional significance to stimuli and events
- Affects the storage of memories and influences recall
Two Threat Processing Pathways
1) Innate and fast-acting thalamo-amygdala pathway, bypasses cortex to elicit immediate autonomic, endocrine and behavioural response (unconscious/implicit processing)
Advantage of emotion driven system: adaptive for survival, diverts attention in presence of threat and danger
Disadvantage of this system: can be too dominating; hasty and potentially irrational reactions that affect goals
2) Slow acting thalamo-cortical-amygdala pathway that supports cognitive appraisal of the meaning of stimuli within context
– react in accordance with goals and social need
- conscious processing through orbital prefrontal cortex
What is the role of the orbito-frontal cortex?
Role in regulating emotional expression and inhibition of inappropriate social behaviour
Connections with the limbic system:
- amygdala may elicit learnt emotional associations
- OFC corrects/adjusts responses (down regulation)
Reasoning about an emotional event can reduce its emotional impact and alter behaviour
Psychological effects of damage to temporal lobe
Personality and emotional behaviour
Pedantic speech, egocentricity, fixed beliefs, obsessiveness, perseveration on conversation topics, paranoia, preoccupation with religion, prone to aggressive outbursts
Prefrontal Cortex (Executive Functions) Dorso-lateral region: ‘Cool EF’
Cognitive flexibility, problem-solving, planning, working memory, prospective memory and complex attention
Prefrontal Cortex (Executive Functions) Ventro-medial region: ‘Hot EF’
Emotional decision making
Reward based learning
Perspective taking - ToM
Prefrontal Cortex (Executive Functions) Orbito-frontal region
Regulating social and emotional behaviour
Learning from experiences (stimulus-response)
Olfaction - smell
Prefrontal Cortex (Executive Functions) dorso-medial region
Motivation and drive
Consequences of damage to dorsolateral cortex
Cognitive deficits/impairments in: Planning and organisation Problem-solving (novel) Alternating and divided attention Mental flexibility Sequencing Rule following and strategy formation Working memory and on-line monitoring Response suppression/inhibition
Consequences of Damage to orbito-prefrontal and ventro-medial prefrontal
Behavioural dysregulation
- Social disinhibition (e.g., lack of tact)
- Lack of spontaneity and stimulus bound behaviour
- Reduced social skills (e.g., reading and responding to social cues)
Personality changes
- Lack of empathy and poor mentalising ability
- Increased or decreased emotional responsivity
- Relatives may perceive the person as “no longer himself”
Brain Regions involved in Empathy
Fusiform Gyrus and amygdala - Emotion recognition
Inferior frontal, inferior parietal & insula - Emotional contagion (shared emotion)
Temporo-parietal junction and medial PFC- Theory of mind and perspective taking
Anterior cingulate and medial PFC - emotional and social response
- Mirror neuron network
- Simulates other’s mental states by directly mapping other’s thoughts, actions, and intentions to the self
Insula - The insula processes emotional response to self and others’ experience of pain(physical and emotional)
Deficits in Empathy
Autistic Spectrum Disorder
Attention Deficit Hyperactivity Disorder
Conduct Disorder and Oppositional Defiant Disorder
Brain injury and dementia
Narcissistic and Antisocial Personality Disorders
Schizoid Personality Disorder and schizophrenia
Borderline Personality Disorder
Emotion Regulation
Cognitive reappraisal
Cognitive reappraisal: reinterpreting an emotion-eliciting event to effectively change its emotional impact - thoughts are altered or the emotion-eliciting stimuli are re-evaluated:
DLPFC (develop cognitive strategy to reframe affective experience)
MPFC and ACC (revaluate internal states and the external stimuli (changes intensity of emotion and physiological response)
Emotional Regulation
Expressive Supression
actively inhibiting the observable expression of the emotional experience by controlling or neutralizing emotional behavior.
OPFC involved in inhibition of inappropriate social and emotional behaviour
What is the relationship between depression and the amygdala?
Abnormal increase in resting activity of the amygdala stimulates cortisol release or stress response
Severity of mood symptoms correlates with increase in glucose metabolism in amygdala
People with depression have over-activity of orbito prefrontal cortex, insula and amygdala of people with major depression
What is the relationship between anxiety and phobias with the amygdala?
Abnormal interactions between the amygdala and PFC
Greater amygdala activation in anxious adults and children, compared to healthy controls, when presented with brief threatening stimuli.
A positive correlation between amygdala activation and anxiety symptom severity.
Increase in amygdala response in anxiety occurs in the absence of a compensatory increase in modulation by the PFC.
Fast-acting thalamo-amygdala pathway dominates, leading to impulsive instinctive behaviours
What is the relationship between PTSD with the amygdala?
People with damage to amygdala less likely to develop PTSD
- differences due to less intense symptoms rather than complete lack of symptoms
Changes in the hippocampus
Early abuse, war and other extreme stress can impair the activity of the hippocampus, a structure very sensitive to stress
Hippocampal volume is reduced in PTSD
Trauma exposure without PTSD may be associated with hippocampal volume deficits
Possible that hippocampal dysfunction leads to distortion and fragmentation of memories
What is neuroplasticity?
The brain’s ability to reorganise its structure, function and connections in response to internal or external stimuli
The lifelong capacity of the brain to change and rewire itself in response to learning and experience.
Occurs in response to positive and adverse life experiences
What is neurogenesis?
Neurogenesis = ability to create new neurons and connections between
neurons (synaptogenesis)
What brain regions are involved in the brains vulnerability to stress?
limbic-hypothalamic-pituitary-adrenal axis- Trauma and maltreatment activates a prolonged biological stress response
PFC and limbic system - The developing brain is particularly vulnerable: prolonged activation of this system leads to structural and functional brain change
