103_18_full - PSYC 103 Winter 2011 Lecture 18 Number Review...

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Unformatted text preview: PSYC 103 Winter 2011 Lecture 18 Number Review session Tuesday Feb. 22 @ 8:00 PM Pepper canyon hall 109 Serial order Terrace et al. (1997) -  Animals construct a spatial representation of 4 slots, in serial order -  Different spatial representations can be integrated… 2 Counting Clever hans Numerical competence Upper end of capability: •  Concept of number: property of all sets with ‘n’ items, Increasing complexity absolute, not relative; may include mathematical properties. (x + y = n ) •  Counting: a sensitivity to the number of things in a set; attachment of ordered labels (“numerons”: in arabic notation “1”, “2”, “3”) •  Subitizing: immediate apprehension of small numbers of items without counting Lower end of capability: •  Numerosity discrimination: discrimination among sets based on how many items they contain (e.g. many vs. few) Perceptual matching: Snapshot of training stimulus remembered: test patterns compared to this. Good match = response Relative numerosity discrimination Honig & Stewart (1989) -  Required pigeons to discriminate 36 red dots (+) from 36 blue dots (-) -  Then tested with patterns of various proportions of red and blue dots -  Direct relationship between proportion of red dots and the rate of responding to that pattern -  Not absolute number of dots – same effect revealed when tested with patterns composed of 16 dots Adapted from Honig & Stewart, 1989. 5 Relative numerosity discrimination from Honig & Stewart, 1989 Relative numerosity generalization gradients for a group of pigeons who were tested with patterns containing either 16 or 36 elements Counting & Absolute number Counting Responses Rumbaugh & Washburn (1993) -  - Trained a chimpanzee to move a cursor with a joystick - Arabic numeral presented (1, 2, 3 etc.) - Arrays of rectangles presented: chimp required to delete the number of rectangles = Arabic number, which it did (eventually!) Counting Sequential Stimuli Meck & Church (1983) Rats rewarded for pressing: - Left lever after 2 pulses of noise - Right lever after 8 pulses of noise - Discrimination solved with ease Breukelaar & Dalrymple-Alford (1998) - Replicated Meck & Church’s experiment - Varied the duration of bursts from trial to trial - Problem could not be solved by timing 7 Counting Control for time (duration) Control for number •  Rats are sensitive to time and number Are time and number coded together? Counting: Time vs number Case 1 Case 2 Conditional time/number discrimination with flashing colored keys: •  if Green, then peck left for 2 flashes, right for 8 flashes, regardless of duration •  if Red, then peck left for 2 sec, right for 8 sec, regardless of number of flashes •  Test with 2-8 pulses over 4 sec (counting), or 4 pulses lasting 2-8 sec (timing) Timing at chance counting at chance Counting sequential stimuli This drop shows that they are counting rewards Rats count small numbers of feeding and transfer this count across food types •  food pellets ➔ cocoa puffs™ •  can count on RR’R’N sequences too Counting simultaneous stimuli Brannon & Terrace, 2000 Sketches of two possible arrangements of the stimuli used in an experiment to study counting in monkeys. Subjects were required to touch the four arrays in each panel in ascending order of the number of dots they contained • Monkeys presented with arrays of patterns • Each pattern contained 1, 2, 3 or 4 objects • Patterns had to be touched in order (1 then 2 etc.) for reward. Position of objects Shape of objects Orientation of objects Varied from trial to trial - Monkeys solved the problem and generalized to novel objects - Zorina & Smirnova (1996) conducted similar study with crows Number The representation of number -  Nominal scale: numbers act as labels (e.g. numbers on a footballer’s shirt) -  Ordinal scale: items can be rank ordered – items in higher rank have more objects than lower rank item -  Interval scale: as an ordinal scale, but also interval between any two adjacent points is the same Experiment by Brannon & Terrace may confirm animal’s appreciation of nominal scales But, On test trials with patterns comprising 4 and 5 objects, 4 was pressed before 5. More than a label? However, Monkeys trained to press patterns in reverse (4, 3, 2, 1) order when tested with 4 and 5, did not press 5 then 4 12 Number Numerical symbols Can animals use different symbols to refer to different quantities? Boysen & Berntson (1989) - Showed a chimp (Sheba) different Arabic numerals from 0-4 - Tray in front of numerals contained number of food items (0-4) - Rewarded for choosing Arabic numeral that = number of food items - Learning transferred to novel items Pepperberg (1994) - African grey parrot (Alex) trained to respond (verbally) to questions 13 Alex Can correctly label novel arrays of items up to 6. Can tell how many items of a certain type are in larger array. Is he subitizing? Counting? Pepperberg (2006) - Alex shown two inverted cups, both of which concealed nuts - Shown objects in turn and asked “How many nut total?” - Correctly responded more than would be expected by chance Counting in chimp (Sheba) 1.  2.  3.  4.  Boysen Match numbers of gum drops to numbers of tokens on cards Match Arabic numerals (on cards) to numbers of gum drops Choose correctly sized array when shown numeral & vise versa (up to 6 or 8 items) Sheba can count the total number of hidden objects & add the numerals on hidden cards! Adding and subtracting Rhesus macaques “looking time” (habituation/dishabituation) Adding and subtracting 5-6 mo old infants ...
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This note was uploaded on 03/24/2012 for the course PSYC 103 taught by Professor Pearlberg during the Spring '07 term at UCSD.

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