Transcript A dilemma for the extended mind

Wilson, “The case for sensorimotor
coding in working memory”
Wilson’s thesis: Items held in short-term verbal
memory are encoded in an “articulatory” format
--in terms of the motor routines used to produce
speech (but not fully executed)
--or the forms used to produced signs, in the case
of sign-language users
The Baddeley and Hitch Model of
Short-Term Memory
Four Short-Term Memory Effects
Phonological similarity: poor recall of similar
sounding items
Word length: longer items harder to remember
Suppression: poor recall when articulatory
mechanism is engaged in competing activity
Irrelevant speech: poor recall with competing
auditory input
Messy Interaction of Effects
Articulatory suppression neutralizes the
phonological similarity effect, but only if
materials are presented in auditory form.
Explanation: When stimulus items arrive in
auditory form, they must be recoded by
articulatory processes. When the items are
delivered in print form, for example, they
can be placed directly in the buffer without
articulatory encoding.
Articulatory suppression neutralizes the
word length effect regardless of the form
of the stimulus items.
This suggests that the word length effect is
always the effect of an articulation
process.
Word Length Effect and Sign
Language
Experiments with temporally long signs
show a word length effect, even when
number of sub-units is controlled for (and
even when the shorter signs have more
sub-units!).
Deaf signers have shorter linguistic memory
span than standard speakers. Individual
signs have longer “articulation” times than
typical words.
Evidence from Nonsigners
--show a length effect when told to speak slowly
--span for digits varies across languages with
average length of digits (in terms of
pronunciation time) (Chinese: shortest
articulation time, largest span; English:
intermediate in both respects; Welsh: longest
articulation time, shortest digit span)
--similar results (intrasubject) with bilinguals
--within-language effect for comparison of vowel
articulation times (‘harpoon’ v. ‘bishop’)
Constant relation: span divided by
articulation time (approx. 2)
Children who pronounce r’s as w’s
systematically make related recall
mistakes (‘wing’ v. ‘ring’)
Wilson concludes that a (possibly innate)
systems of linguistic encoding lies behind
all of these effects.
Richardson et al. Preliminary study
Two experiments:
--choose the rebus sentence that most naturally
reflects the meaning of a verb
--generate image schemas corresponding to verbs
--two sets of results show a significant item-byitem correlation between angles associated with
verbs
Experiment one
Hypothesis: non-specific imagery activated by verb
comprehension will interfere with performance
on a visual task if the imagery shares its axis
with the visual task.
Design: Subjects hear sentences through
earphones. After brief, varied interval (50-200
ms), subjects must identify circle or square
presented on either horizontal or vertical axis
relative to fixation cross.
Results
Reaction times are slower when the circle or
square to be identified fall along the same
axis as the one associated with the verb in
the preceding sentence.
Difference is significant but appears to be
due primarily to the effect of verb-type on
the identification of test stimuli along the
vertical axis.
Experiment 2
Study trials: Subjects hear sentences read while
viewing sequentially presented pictures of the
agent and patient (subject and object); all
pictures are centrally located.
Test trials: Two pictures are presented
simultaneously in either horizontal or vertical
alignment. Subjects must indicate whether the
two pictures were associated with the same
sentence during the study phase.
Results
No effect of axis-based match or mismatch on
accuracy or response; memory that two pictures
were paired was high across the board.
Reaction times showed interaction between verb
orientation and stimulus orientation. In
particular, accurate responses were significantly
faster when the paired pictures were presented
along the vertical axis and the vertical axis is
associated with the verb in the relevant
sentence.
Conclusion
Linguistic meaning has some spatial
component.
Spivey and Geng, Psychological
Research, 2001.
Experiment 1:
Subjects heard stories with a directional
component while their eye movements
were tracked.
While listening to the stories, subjects’ eye
movements tended to track the dynamics
of the stories.
Experiment 2
Participants saw four shapes of varying color and
orientation in four corners of a 3×3 grid. The
screen went blank for a moment, and then only
three of the shapes returned. Participants were
asked a question about the orientation or color
of the missing shape.
Participants made a saccade to the blank location
of the grid where the queried shape had once
been, despite the fact that there was clearly no
useful information present there.
Richardson and Spivey, “Representation, space
and Hollywood Squares: looking at things that
aren't there anymore,” Cognition, 2000.
Reported similar findings to experiment 2, using a
4x4 grid. A talking head appears in only one cell
(others are blank) and describes a brief
sequence of events. Later, when subjects are
asked about the events, they focus on the
corresponding cell, even though the screen is
blank.