A team of scientists from Canada and the United States found that perception of weight is related to context, and distractions interfere with conscious formation of memories.
An important condition for the effectiveness of manipulations with material objects is a person's ability to predict their hidden physical parameters, for example, weight. It is known that two types of memory are involved in weight estimation: associative and sensorimotor. Perceiving the weight of an unfamiliar object involves associative memory, which is based on comparison with previous experience and is more conscious, while sensorimotor memory allows the representation to be unconsciously adapted to new variables, including dimensions. According to past works, on average, such adaptation occurs within 5–40 interactions, but its mechanism has not been sufficiently studied. In addition, it is unclear whether a person's condition and context influence weight estimates.
A classic example of misperception of mass is the weight-size illusion, which is that a small object, when compared to a larger one, tends to appear heavier than it is. It is believed that this is due to the comparison of the estimated weight with a large and, as a result, massive object. To test how the weight-size illusion relates to context, experts from Queens University and Michigan Technological University conducted a series of experiments with 49 volunteers aged 18–33 years. Four plastic cylinders were used as a stimulus material: large (82 millimeters high and 82 millimeters in diameter) but light (190 grams), small (51 millimeters high and 51 millimeters in diameter) but heavy (750 grams), and two cylinders of the same size weighing 455 grams.
Experiment design / © Kevin M. Trewartha et al., Cognition, 2017
In the first stage, the participants evaluated the weight of the first two cylinders by alternately lifting them with their fingers (while also indicating subjective effort) or placing them in the palm of their hand. Then the authors repeated the experiment with inverted cylinders: despite their different sizes, their mass remained identical. After that, additional incentives were introduced into the methodology. While holding the cylinders, one group of volunteers had to simultaneously solve simple arithmetic problems, in particular, aloud subtract seven from each number called by the researchers (from 12 to 99). The results of both measurements were compared with the objective mass of objects, reaction time and accuracy of responses.
Analysis showed that the way the cylinders were manipulated did not correlate significantly with the concept of weight. At the same time, the parameter score significantly improved after five sessions for active lifting, but earlier - during the third or fifth session - for passive retention. At the same time, the need to simultaneously perform a third-party task had little effect on the indicator. Thus, the authors came to the conclusion that the estimate of the weight of the experimental cylinders was weakened by a similar experiment with cylinders of different masses. At the same time, arithmetic tasks requiring conscious control slowed down learning. According to the authors, the data obtained clarify the mechanism of interaction between associative and sensorimotor memory. Despite the fact that concomitant factors do not significantly interfere with the formation of stable memories,they can interfere with a person when trying to consciously record certain events.
Details of the work are presented in the Cognition magazine.
Denis Strigun
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