Timing and Counting

Psychology 3906

Introduction

• Just like spatial stuff in a sense• Time passes• Would make sense to be able to encode

this• Would make sense to respond to this• Both long and short intervals have been

studied

Circadian timing

• Much of what happens on this planet depends on the time of day

• From fungi to humans, our baheviour is rhythmic

• Studied through entrainment– Synchronizing the external and the internal– Endogenous rhythms are a tad more or

less than 24 hr

What makes entrainment special?

• Agent acts in absence of other cues

• Rhythms adjusted

• Stable phase relationship

• Removal changes pattern

genes

• Tau in hamsters

• Per in drosophila

• Genetic structure almost the same which is fracking cool

Interval timing

• Seconds or minutes rather than hours

• Train the animal to an FI

• Peak procedure with empty trials

• Weber’s Law

• Resetting

Other theories

• Connectionist modeling and oscillators

• BeT

• BeT not so good on trial by trial data

• Connectionist model may be the best

Counting

• Seems unlikely to some, but why not?

• Many - few discriminations

• Olthoff, Iden and Roberts (1997)

Conclusions

• Animals have abilities that may surprise us

• However, we should not be surprised, keeping track of time and number is really important for things like foraging