Biomedical subjects

Doug Rohrer

Publications and source records attributed to Doug Rohrer.

4 recordsLinked to original sources

PubMed2003

The natural appearance of unnatural incline speed.

In three experiments, college students provided judgments about a marble's speed along a nonlinear incline. Each experiment revealed widespread support for the slope-speed belief, a mistaken belief holding that an object's speed at any point depends on the slope at that point. In truth, an object's incline speed varies with its elevation. In Experiment 1, participants relied solely on a diagram. In Experiments 2 and 3, participants observed computer animations depicting the descent of a marble at speeds conforming to either the slope-speed belief or Newtonian theory, and they rated the slope-speed version as more "natural" than the correct version. The task in Experiment 1 gauged participants' consciously available knowledge, but the perceptual realism of the slope-speed animations suggests that the slope-speed belief is also held outside awareness. By contrast, virtually all previously identified false beliefs about motion appear unnatural once animated.

Adult↗

PubMed2003

Concurrent task effects on memory retrieval.

Previous studies combining continuous free recall with a concurrent task have generally shown that concurrent tasks impose fairly negligible effects on memory retrieval. By contrast, dual-task studies employing either cued recall or semantic retrieval reveal gross memory impairment and suggest that retrieval is delayed by the centrally demanding phase of the concurrent tasks (i.e., response selection). To explore this conflict, subjects performed continuous free recall while carrying out a serial-choice-response time (RT) task, as in the previous free recall studies. Unlike these previous studies, however, the choice-RT task utilized arbitrary stimulus-response mappings in order to increase the proportion of time devoted to the centrally demanding response selection phase. Recall total was reduced significantly, and recall latency was slowed substantially.

Adolescent↗

PubMed2002

The breadth of memory search.

The recall of previously studied items is widely believed to incorporate a search of a markedly constrained set of possibilities, and the present study examines whether this set of items typically includes unstudied semantic associates of the study items. In an episodic task, participants recalled a previously studied list of eight exemplars drawn from a small or large category, and, in a semantic task, participants generated exemplars from these categories. Category size affected the time course of recall in the semantic task but not in the episodic task. This empirical dissociation between episodic and semantic memory is consistent with the view that episodic memory search efficiently excludes unstudied semantic associates of the study items and is instead constrained to those items sharing the temporal and spatial attributes of the episode.

Adult↗

PubMed2002

Misconceptions about incline speed for nonlinear slopes.

In 3 experiments, college students provided qualitative predictions about a marble's speed along nonlinear inclines. When predicting the outcome of a race between identical marbles along differently shaped ramps, most students predicted incorrectly that the shorter path was necessarily quicker (the shorter-quicker belief). When comparing instantaneous speed at 2 points, most students predicted incorrectly that incline speed depended on the slope at that point (the slope-speed belief). A final experiment provides evidence that the slope-speed belief reflects a deeper fallacy regarding the resistance encountered while traversing inclines and lifting objects. This fallacy also predicts the prevalent belief that heavier objects fall faster than lighter objects during incline descent or free fall.

Female↗