Representation of Number

Question 1

What is the numerical distance effect?

Answer 1

Accuracy increases and RTs decrease with greater numerical distance. Example: It’s easier to say 8 > 3 than 5 > 3

Question 2

What is the numerical size effect?

Answer 2

When numerical distance is held constant, performance decreased with increasing numerical magnitude. RTs are longer to say 9 > 7 than to say 5 > 3.

Question 3

Do infants and monkeys have a “sense of number?” What is some evidence in favour of your answer?

Answer 3

Humans and monkeys show similar effects. Suggests that the NDE is not reliant on linguistic representations. Infants gaze back and forth when quantity of dots the difference is bigger

Question 4

How is area LIP related to representations of number?

Answer 4

Neurons in area LIP of the macaque monkey fired monotonically with increasing or decreasing numbers of dots. Had no experimental training with numbers.

Question 5

Describe three pieces of evidence linking the intraparietal sulcus to the represent numbers or quantities.

Answer 5

Numerical deficits in Turner’s Syndrome are linked to abnormal development of the inferior parietal sulci.
Right intraparietal sulci.
-Odd vs. even classification.
-Comparing a number’s magnitude to a standard value.
-Ordinal values
-Subtraction (greater than for X or +, suggesting that those operations are memorized).
-“Two” and “2” both activated the IPS.
Part of the IPS habituates to numerosity. Recovery of activity is influenced by the numerical distance from the habituated value.