Memory, Attention, and Executive Functioning (1) (1)

Administrative Details

  • Test Information: Next week, October 22, 2024

  • Format: In-person at the university during the course.

Memory, Attention, and Executive Function

Memory Types

  • Future Anterograde Amnesia: Inability to form new memories following a time point of brain injury.

  • Retrograde Amnesia: Inability to access old memories; may be incomplete, with preserved older memories available while more recent memories are not.

Memory Definitions

Declarative/Explicit Memory

  • Episodic Memory: Autobiographical memories of life events.

  • Semantic Memory: Facts and general knowledge.

Nondeclarative/Implicit Memory

  • Procedural Memories: Skills and tasks that do not require conscious thought.

Childhood Amnesia

  • Characterized by the inability to recall events from the first 4 years of life and difficulty recalling events from the first decade.

  • Possible causes include cognitive development and increased hippocampal neuron proliferation that disrupts stored memories.

Types of Explicit Memories

  • Episodic and Semantic: Deficits in episodic memory are particularly severe in bilateral temporal lobe amnesia.

Memory Stores

  • Short-term Memory (Working Memory): Involves temporary retention of information.

  • Long-term Memory: Capacity to learn and retain new information.

  • Sensory Memory: Brief storage of sensory information.

Memory Processes

  • Encoding: Initial processing of information.

  • Long-term Storage: Maintenance of information over time.

  • Retrieval: Process of accessing stored information.

Declarative Memory Structure and Clinical Features

Important Structures

  • Damage to brain areas may affect memory functionality.

Hemispheric Encoding and Retrieval Asymmetry

  • Left Hemisphere: Engaged in encoding and recall processes.

  • Right Hemisphere: Also plays a role in memory retrieval but in different contexts.

Case Study: H.M.

Background

  • Pre-surgery History: Suffered from severe epilepsy, focused in both medial temporal lobes.

  • Surgical Intervention: Bilateral medial temporal lobectomy, including removal of hippocampus and amygdala.

  • Post-surgery Outcomes: Reduced seizures but profound anterograde amnesia and minor retrograde amnesia.

Formal Assessment and Unconscious Memories

  • Tests included digit span, block-tapping, and mirror drawing, which demonstrated H.M.'s retention of tasks despite lack of conscious memory.

Mirror Drawing Task Insights

  • H.M. performed well in learning mirror drawing but had no recall of previous exercise.

Incomplete Picture Test

  • Participants identify fragmented objects over different trials, assessing explicit and implicit memory.

Pavlovian Conditioning

  • Explored associations made through conditioned responses (e.g., air puff response).

Impact of Brain Damage on Memory

Korsakoff's Syndrome

  • Caused by thiamine deficiency due to chronic alcohol consumption, leading to severe amnesia.

  • Damage primarily associated with the mediodorsal nuclei of the thalamus.

Alzheimer’s Disease

  • Characterized by initial mild memory loss, advancing to incapacity.

  • Pathological changes include reduced acetylcholine production and degeneration in the basal forebrain.

Neuroanatomical Structures in Memory

  • Implicit memory structures show decreased activity when declarative memory is impaired.

  • Healthy controls perform well on artificial grammar tasks despite amnesia.

Differences between Short-term Memory (STM) and Long-term Memory (LTM)

Short-term Memory Characteristics

  • Relies on phonologic coding and has limited capacity.

Long-term Memory Characteristics

  • Utilizes semantic coding and has theoretically unlimited capacity.

Relationship between STM and LTM

  • Memory systems may share anatomical structures yet function distinctly.

Case Study: KF

  • Examined brain damage related to recall capabilities in verbal versus visual formats.

From STM to Working Memory

  • STM acts as a passive storage system, while working memory is an active processing unit.

Attentional Systems

Definition of Attention

  • General alertness or capacity to focus.

Neuroanatomy of Attention

  • Different neural networks support sustained and selective attention.

Types of Attention

  • Alternating Attention: Task-switching capability.

  • Divided Attention: Allocating focus across multiple tasks (e.g., multitasking).

Executive Functions Overview

Functions of Executive Functions

  • Involves planning, flexibility in problem-solving, working memory, autonomous attention allocation, and behavioral self-assessment.

Developmental Considerations in Executive Functions

  • Growth trajectories noted in early childhood (5-8 years), continuing into later childhood.

Brain Circuits Related to Executive Functioning

Dorsolateral Prefrontal Cortex

  • Implicated in emotional and motivational behavior.

Orbitofrontal Cortex

  • Important for emotional regulation and learning social contingencies.

Clinical Cases of Akinetic Mutism

  • Explored differential diagnoses and the clinical manifestations of this condition.

Theories of Emotion

James-Lange Theory

  • Emphasizes physiological responses as precursors to emotional experiences.

Cannon-Bard Theory

  • Proposes simultaneous experience of emotion and physiological response.

Basic Emotions Classification

  • Primary Emotions: Basic feelings like happiness, sadness, fear, disgust, anger, and surprise.

  • Secondary Emotions: More complex emotions like guilt, pride, and regret.

Emotion Expression

  • Involves different brain regions; spontaneous emotions linked to subcortical structures while cued emotions to cortical areas.

Fear Response Conditioning

  • Fear responses are formed through two primary pathways: thalamo-amygdala and thalamo-cortico-amygdala.