Biomedical subjects

J Broerse

Publications and source records attributed to J Broerse.

14 recordsLinked to original sources

PubMed1992

Anomalous spiral aftereffects: a new twist to the perception of rotating spirals.

Stationary spirals viewed after inspecting rotating sectored disks appear to rotate and to expand or contract radially, even though the rotating disks contain no perceptible components of radial motion. Moreover, the relative directions of illusory rotation and radial motion observed in these instances are 'impossible' under the stimulus constraints normally imposed by the geometry of a spiral under rotation: the stationary spirals appeared to expand/contract in directions opposite to those normally observed under conditions of actual spiral rotation, and under conditions of illusory spiral rotation in classical spiral aftereffects.

Discrimination Learning↗

PubMed1992

The apparent shape of afterimages in the Ames room.

When observers project afterimages of circular patterns onto a surface slanting away from them the images are reported as being oval in shape. In this paper it is reported that this does not occur when similar afterimages are projected onto the slanting rear wall of an Ames room. Instead of appearing as ovals, the afterimages remain circular. It appears as though the actually-slanted rear wall of the room not only looks as if it is normal to the line of vision, but also that it functions as if it was in such an orientation as far as a projection surface for afterimages is concerned. While these results are consistent with Emmert's law and with traditional accounts of shape and size constancy, they raise once again the age-old issue of whether the 'image on the retina' constitutes an object of perception that can be described in terms of its shape or size.

Adult↗

PubMed1992

Local and global aspects of temporal patterning in the conversations of adults.

A randomization procedure was used to examine local and global aspects of patterning in the conversations of 25 pairs of students. This procedure involved reorganizing the binary events constituting the partners' individual records, and then combining these events to produce randomized dyadic records of each conversation. Comparisons between the observed and randomized records indicated an overall tendency in all dyads to avoid covocalization (simultaneous talk). Notwithstanding this overall tendency, there were gender-related differences between groups; dyads containing female participants tended to covocalize more frequently, and for longer durations, than male-male dyads. There was also a tendency for participants to respond promptly to the talk of their partners. We interpret these results as indicating that systematic variation in the use of covocalization may occur at local levels within the constraints set by information-processing requirements at global levels.

Communication↗

PubMed1990

Emmert's law in the Ames room.

The Ames distorted room illusion, in which the perceived sizes of objects placed within the room differ from their objective sizes, has been used to support arguments for indirect perception. A study is reported in which Emmert's law of the apparent size of after-images was examined in relation to the Ames room's illusory alteration of apparent and actual distances. Size judgments of afterimages projected into the Ames room were compared with control conditions in which both actual and apparent afterimage projection distances were reproduced. Results indicate that Emmert's law may not provide a simple geometrical relationship between proximal image size and actual viewing distance, and that the processes involved in making afterimage size judgments are similar to those processes involved in making size judgments of 'real world' objects.

Adult↗

PubMed1989

Timing in mother-infant communications: a comment on Murray & Trevarthen (1986)

Murray & Trevarthen (1986) experimentally manipulated the behaviours of mothers and infants in an attempt to determine who is responsible for the fine temporal patterning during vocal engagements. In the present note it is argued that the measures of content and style of maternal talk used by Murray and Trevarthen do not directly indicate the ways in which the behaviours of the partners are combined on a moment-to-moment basis.

Female↗

PubMed1988

Aspects of structure and content of maternal talk with infants.

Content of maternal talk in six mother-infant dyads was used to determine whether mothers timed their talk to infants as they would when conversing with an adult. Results indicated that maternal talk of an informative nature (Type 1 acts) tended to follow a brief intervening interval of silence, while maternal talk containing little or no information (Type 2 acts) tended to occur when the mothers "talked with" (covocalized with) their infants. In addition, there was a significant trend for the overall proportion of Type 1 acts to increase over infant age. These findings support the view that, during mother-infant engagements, mothers behave like sophisticated conversational partners.

Child Language↗

PubMed1986

Maternal control of co-vocalization and inter-speaker silences in mother-infant vocal engagements.

Co-vocalizations and inter-speaker silences were used to investigate the vocal engagements of six mother-infant dyads. Observed records of vocal behaviours were compared with records in which the vocal behaviours were randomized. The results indicated that there were significantly fewer co-vocalizations in observed than in randomized records; that the durations of inter-speaker silences following infant vocalization were significantly shorter in observed than in randomized records; and that the durations of inter-speaker silences following maternal vocalization were significantly longer in observed than in randomized records. These findings were interpreted as being consistent with the view that mothers attempt to engage their infants in turn-taking encounters, and that descriptions of such engagements in terms of conversational metaphors may be misleading in this regard.

Female↗

PubMed1986