Depression, Memory, and Brain Aging Flashcards

Vocabulary-style flashcards covering depression categorization, memory systems, and neurocognitive theories of aging based on the lecture transcript.

Early-onset depression

A form of depression that debuts early in life, often before $60\text{--}65$ years of age, and is frequently linked to higher heritability and genetic vulnerability.

Late-onset depression

Depression debuting after age $60\text{--}65$, which is less linked to genetics and often associated with brain changes like vascular disease or structural changes in the hippocampus.

Dysfunction in the HPA axis

A biological disturbance in depression involving elevated levels of cortisol and CRH, where higher cortisol levels correlate with more severe symptoms.

Neurochemical disturbances

Lower levels of neurotransmitters such as serotonin, noradrenaline, and dopamine associated with depression.

Loneliness

A psychosocial risk factor for older adults involving low social support and loss of social roles, strongly linked to both the onset and poorer prognosis of depression.

Positive bias

The tendency in older adults to focus more on positive stimuli and avoid negative ones, contributing to improved emotion regulation and reduced anxiety.

Associative deficit hypothesis

A theory by Naveh‑Benjamin stating that aging particularly affects the ability to bind together different pieces of information into a coherent episodic memory representation.

Item memory

Memory for single units, such as recognizing a face or a word, which remains relatively preserved in older adults compared to associative memory.

Strategy-based training

A cognitive intervention using external support and memory strategies like associative visual imagery, the method of loci, or chunking to improve performance in specific tasks.

Process-based training

Training a cognitive process, such as working memory, with the intention of improving general cognitive capacity rather than specific task performance.

Working memory

The ability to temporarily store and manipulate information, often assessed using the Digit span test.

Episodic memory

Conscious memory for personally experienced events in time and space, typically assessed by free recall, cued recall, and recognition.

Semantic memory

Memory for facts, concepts, and word meanings, which is generally preserved or improved with age.

Procedural memory

Memory for skills and procedures, such as learning to play a melody, which is minimally affected by normal aging.

Priming (implicit memory)

The unconscious influence of prior experience on performance, often tested using word‑stem completion tasks.

Prospective memory

Memory for future intentions, such as remembering to press a button in $10\,\text{minutes}$ during a laboratory task.

First-in-last-out hypothesis

The hypothesis stating that brain regions that develop late, such as the frontal cortex, also deteriorate early in the aging process.

Disconnection hypothesis

The theory that age‑related cognitive decline is due to impaired communication between brain regions caused by reduced white‑matter integrity.

HERA model

A model describing lateralized frontal activations in younger adults, where the left side is used during encoding and the right during retrieval.

HAROLD model

A model describing the bilateral activation seen in the frontal lobes of older adults during memory tasks, interpreted as compensation or dedifferentiation.

Recollection

A detailed memory process central to the hippocampus that often declines with age.

Familiarity

A 'sense of knowing' linked to parahippocampal (rhinal) regions, which older adults often rely on to compensate for hippocampal decline.

Default mode network (DMN)

A brain network that should be deactivated during cognitive tasks; in older adults, its deactivation is often weaker and slower.

Dedifferentiation

A process of reduced neural specialization that may explain why older adults show bilateral frontal activations.