KNES385 Exam 2

Executive Functions

Refers to a family of top down mental processes needed when…

•  You have to concentrate and pay attention

• When going on automatic or relying on instinct or intuition would be ill advised, insufficient, or impossible

3 core executive functions

1. working memory

2. cognitive flexibility

3. inhibitory control

higher level executive functions

1. problem solving

2. high level planning

3. reasoning

reasoning

Ability to reach logical conclusions based on prior info

problem solving

Constructing and applying mental representations of problems to finding solutions to those problems that are encountered in nearly every context

High Level Planning

Considers actions and their sequential interdependence in terms of the desirability of their outcomes

• Ex: when I am trying to decide when is best to self tan

What part of the brain is critical for executive functions?

Prefrontal Cortex

Inhibitory control

Being able to control your attention, behavior, thoughts, emotions to override a strong internal predisposition or external lure

• doing what is needed

• behavioral (self control), thoughts/memories (cognitive inhibition), attention (selective vs focused)

Working Memory

Limited capacity system that temporarily stores and uses recently presented information

• information is manipulated

• 7 (±2) items at a time for 20-30 seconds before losing some information

Short term memory

limited capacity system with no manipulation

Long Term Memory (LTM)

more permanent info storage with unlimited capacity, info about specific past events or general knowledge

• 3 subsystems: Semantic, Episodic, Procedural

Semantic LTM

Stores general knowledge (facts, concepts)

• declarative/explicit

Episodic LTM

Stores info about personal experiences and their temporal associations

• mentally travel back in time

• declarative / explicit

Procedural LTM

How to do something (like riding a bike)

Declarative Knowledge

what to do in a situation, verbalizable

• ex: The rules of chess

Procedural Knowledge

Knowledge that enables someone to perform a skill, not verbalizable

• ex: riding a bike, typing, driving

Encoding

Transforming to be remembered info into a form that can be stored into memory

Storage

Placing info in long term memory 

Rehearsal

Enables a person to transfer info from working memory to long term memory 

Retrieval

Searching through long term memory for info needed for present use

Forgetting

Loss of memory, inability to retrieve info from memory

Decay

Memory representation deteriorates over time and interferences 

Attention

• Characteristics assoc w/ consciousness, awareness and cognitive effort as they relate to the performance of a skill

• Select the most relevant stimuli while filtering out less relevant information

  • Helps us respond quickly to critical env changes

  • Helps us achieve behavioral goals more efficiency 

• Limited … influences performance when we do more than one activity at the same time

Fixed Capacity Model

Single fixed capacity channel (resource)

Flexible Capacity Model

• Attention capacity should not be considered fixed as task requirements change

• Available attention that can be allocated to a task is a pool of effort

  • This can be distributed to several activities at once

• arousal is a factor

Bottleneck / filter Theory of Attention

• Filters out info not selected for further processing

• Filter theories differ in terms of where the filtering takes place

Multiple resource theory

• presence of many attention mechanisms, each w/ limited resource and different functions

• Performing diff tasks simultaneously depends if they require attention from a common source, or diff sources 

Top Down (endogenous) Attentional Processing

Internally induced process in which info is actively sought out in the env based on voluntary chosen factors

• visual search is the process of actively directing visual attention to locate relevant info

Bottom up (exogenous) attentional processing

• Externally induced process in which info is selected automatically bc of highly noticeable features of stimuli (internal)

Attentional Focus

• Directing of attention to specific aspects of our performance or env

• width (broad/narrow), direction (internal/external), switching

Automaticity

• Performance of a skill or its parts w/ little to no demand of attention capacity

  • influence by experience/practice

Prefrontal Cortex (PFC)

• Involved in info processing w/ high level of integration 

• Important for

  • Exec functions (inhibitory control, working memory, cognitive flexibility)

  • Selecting an appropriate response

  • Anticipation of action consequences

  • Sequencing behavior over time

Premotor Cortex (PMC, Area 6)

2 parts: LPMC, SMA

• Involved in

  • Eliciting complex movements (multijoint motion, hand shaping

• Receives input from basal ganglia and cerebellum 

  • Via thalamus 

• All premotor areas project to the spinal cord

• Corticospinal projections from the SMA innervate the digit and hand muscles 

  • Premotor areas therefore can control hand movements independently of the primary motor area 

• Dense interconnections btw premotor/prefrontal areas allow working memory to influence specific aspects of motor planning

Supplementary Motor Area (SMA)

Part of PMC

involved in

• control of distal muscles and bilateral movement

• planning movement sequences from memory

  • no visual cue = internally initiated

• neural shift from SMA —> primary motor cortex when proficiency increases

Lateral Premotor Cortex (LPMC)

Controls prox + dist muscles

involved in planning

• mvmt based on EXTERNAL sensory input

• hand shape to object

active btw anticipatory cue and signal to move

receives input from PFC

• access to working memory info about spatial location of object

Primary Motor Cortex (Area 4)

• Controls GROUP OF MUSCLES to move entire segment

• elicits simple movements of single joints

• active BEFORE mvmt onset and THROUGHOUT mvmt duration

• encodes mvmt direction and force

• cross over + contralateral mvmt

Corticospinal Tract

• Lateral Pathway (voluntary)

• carries neural drives for vol mvmt

• only direct cortex - motor neuron pathway!!!

• controls fine digits of the hand

Rubrospinal Tract

• lateral pathway (voluntary)

• alternate pathway for motor drive

• red nucleus recives

  • most input from cerebellum

  • some input from motor cortex

    • this allows for some recovery after damage to corticospinal tract

Tectospinal Tract

• Ventriomedial Pathway (balance/orientation)

• coordinates audiovisual info

• reflective turning of head to orient to stimuli

Vestibulospinal Tract

• Ventriomedial Pathway (balance/orientation)

• postural adjustments

• Eye mvmt (VOR)

• head mvmt

Reticulospinal Tract

• Cortical neurons synapse on reticular neurons

• regulates sensitivity of reflexes

• activates CPG