Psy332: Human Cognition PP3 Short Term Memory

Sensory info

Sensory info is changed into type of info understood/compatible with nervous system (pattern of action potentials firing)

-this occurs in the correspondinng sensory cortex (visual, auditory, tactile) of the brain

Iconic memory

momentary sensory for visual info

Echoic memory

Momentary sensory for auditory (hearing)

Short term memory

It has limited space for storing info. Storage is fragile bc distraction can cause forgetting

-This is the encoded form taken from sensory memory. there can be some processing or operations performed on the info before being sent to long term memory

Miller (1956) short term memory theory

Identified short term memory can store 7 +/-2 pieces of info

-Storage capacity in short term memory can be measured through a digit span task or a memory span task

-eventually, STM getss filled up and takes out info to store new incoming info (displacement)

Transfer of info from STM to LTM (Glanzer and Cunitz, 1966) Evidence

-serial position effect

-primacy effect

-recency effect

Serial position effect

If presented a list or series of items to remember, remembering a particular item is related to its position on the list. People have a tendency to remember early and late info in the list

Primacy effect

In free recall, items presented at the start of the sequence are remembered well (Initial info in STM was sent to LTM for storage through rehearsal (Rundus and Atkinson, 1970)

Recency effect

In free recall, items presented towards the end of the sequence are remembered well (last info stored in STM)

Working Memory Model (Baddeley and Hitch, 1974) Central Executive Components

-Phonological Loop

-Visuo-spatial sketchpad

-episodic buffer

Central Executive (Baddley and Hitch, 1974)

A component of attention that controls decision processes about currently stored info, engages in rehearsal to send info into LTM and engages in retrieval of info from LTM (these processes makes language and reasoning possible)

Phonological loop

Visuospatial sketchpad

Episodic buffer

This is dedicated to linking or integrating info across multiple modalities to form integrated units of visual, spatial, and verbal info with time sequencing (or chronological ordering) such as memory of a story or a movie scene

Evidence for the visuospatial sketchpad: Shepard & Metzler (1971)

Mental rotation of shapes (The larger the difference between the angle of rotation between a target and a comparison object, the longer people can confirm if they are the same object

Evidence for the phonological loop

Kroll et al (1970) participants were given a shadowing task. At some point, a letter was presented for later recall. The letter was presented in a visual modality (on a computer screen) or auditory modality (a distinct voice in the shadowed message)

-Memory accuracy for the letter in the visual modality was maintained despite time delays

Evidence for the phonological loop Baddeley, Thompson & Buchanan (1975)

Asked participants to recall sets of 5 words in correct order. Researchers found a advantage of recalling short words compared to long words (word length effect)

Evidence for episodic buffer

(Badelely & Wilson 2002)

Patients with amnesia, who presumably have no ability to encode new info in long term memory, nevertheless have good short-term recall of stories, recalling much more info than could be held in the phonological loop

The brain and working memory with the central executive

The prefrontal cortex contains the supervisory attentional system

The brain and working memory with phonological loop

The brain and working memory with visuo-spatial sketchpad

Damage to the regions in the temporal lobe causes a disruption in the visuo-spatial sketchpad