Biomedical subjects

Kathleen M Silva

Publications and source records attributed to Kathleen M Silva.

3 recordsLinked to original sources

PubMed2006

Humans' folk physics is not enough to explain variations in their tool-using behavior.

Two experiments examined adult humans' folk physics (i.e., their naturally occurring and spontaneous understanding of the physical world) using variations of trap-table problems used to study chimpanzees' folk physics. When presented with these problems, people unnecessarily avoided retrieving a reward by pulling a rake on the side of a table with a trapping hole--even though it was highly unlikely that the hole would trap the reward. However, when the distance between the reward and the trap was sufficiently large and the distance that the reward had to travel to be retrieved was sufficiently short, people preferred to retrieve a reward by pulling the rake on the side of the table with the trap. These results underscore that behavior during tool-use tasks has many possible causes, only one of which might be a subject's folk physics.

Choice Behavior↗

PubMed2005

Methodological-conceptual problems in the study of chimpanzees' folk physics: how studies with adult humans can help.

In three experiments, we examined humans' folk physics (i.e., a naturally occurring and spontaneous understanding of the physical world), using variations of problems used to study chimpanzees' folk physics. Presented with trap-tube problems in two experiments, adult humans showed an unnecessary bias to insert a stick into the end of the tube farthest from the reward to push it out the other end. When presented with trap-table problems with ineffective trapping holes, people unnecessarily avoided the side with the hole. The similarity of humans' and chimpanzees' behavior on these tasks highlights methodological and conceptual problems in studies of chimpanzees' folk physics and suggests alternative explanations for their behavior.

Adult↗

PubMed2005

A behavior systems view of the organization of multiple responses during a partially or continuously reinforced interfood clock.

We examined how a 50% Pavlovian partial reinforcement (PRF) schedule, versus a 100% continuous reinforcement (CRF) schedule, altered the asymptotic amount and distribution of focal and general search behavior in rats during 48-sec trials with and without a four-segment interfood clock (S1-S2-S3-S4-US). Under CRF, but not PRF, average asymptotic focal search (nosing in the feeder) increased across the last two clock segments (S3 and S4), and more for the clock group than the no-clock group. Locomotor general search peaked in the second clock segment (S2) for the CRF-clock and CRF-no-clock groups and in S3 for the PRF-clock groups. Furthermore, the ratio of general search to maximum focal search was higher for the PRF-clock group than for the CRF-clock group. This pattern of results supports the view that predictable reward presentations temporally organize search states and related responses between food presentations. The relative expression of these responses varies with the predictability and proximity of reward and is more sharply defined in the presence of a clock.

Animals↗