Biomedical subjects

T L Hubbard

Publications and source records attributed to T L Hubbard.

At least 19 recordsLinked to original sources

PubMed2001

The effect of height in the picture plane on the forward displacement of ascending and descending targets.

The effect of height in the picture plane on the remembered location of ascending or descending targets was examined. Consistent with previous research, memory was displaced forward in the direction of motion. The magnitude of forward displacement was larger for targets low in the picture plane than for targets high in the picture plane, and this was observed with ascending motion and with descending motion. This pattern is consistent with the hypothesis that memory for the location of ascending or descending targets is biased by the effects of implied gravitational attraction on the velocity of those targets, and some implications of such a bias for issues in mental representation are noted.

Adult↗

PubMed2001

Representational momentum and Michotte's (1946/1963) "launching effect" paradigm.

In A. Michotte's (1946/1963) launching effect, a moving launcher contacts a stationary target, and then the launcher becomes stationary and the target begins to move. In this experiment, observers viewed modifications of a launching effect display, and displacement in memory for the location of targets was measured. Forward displacement of targets in launching effect displays was decreased relative to that of targets (a) that were presented in isolation and either moved at a constant fast or slow velocity or decelerated or (b) that moved in a direction orthogonal to previous motion of the launcher. Possible explanations involving a deceleration of motion or landmark attraction effects were ruled out. Displacement patterns were consistent with naive impetus theory and the hypothesis that observers believed impetus from the launcher was imparted to the target and then dissipated.

Acceleration↗

PubMed2001

Musical scales and evaluations of happiness and awkwardness: effects of pitch, direction, and scale mode.

Participants rated the perceived happiness, brightness, awkwardness, pitch velocity, and tempo change of ascending and descending musical scales in four modes (natural, melodic, and harmonic minor modes and the major mode). Only minor differences between ratings of natural, harmonic, or melodic minor scales or between ratings of parallel and relative major scales were found. Ascending scales were rated as happier, brighter, and more accelerating than were descending scales; ascending minor scales were rated as faster and more awkward than were descending minor scales. Musical keys in each mode were compared, and significant differences were found. Musical keys that started on a higher pitch were rated as happier, brighter, and faster and as speeding up more than were keys that started on a lower pitch. The data were consistent with previous findings and suggest that pitch and direction (contour), rather than mode or key, influence listeners' judgments of musical stimuli.

Auditory Perception↗

PubMed2001

Recognizing the component tones of a major chord.

Listeners judged whether a target tone was contained within a previously or subsequently presented major chord, and targets consisted of either the root, third, fifth, or tritone of the scale based on the root of the chords. Chord position influenced the relative recognition of targets, but listeners exhibited greater recognition of the fifth regardless of chord position (root, first inversion, second inversion). The data were not consistent with notions of root tracking or melody tracking. The data were broadly consistent with the notion that different chord positions may be harmonically equivalent (i.e., that listeners may recognize components of a chord regardless of chord position), with notions of analytic set and the importance of an instantiation of musical context for chord processing, and with the importance of the fifth in harmonic progression.

Adult↗

PubMed2000

Spatial memory averaging, the landmark attraction effect, and representational gravity.

The effect of a large stationary landmark on memory for the location of a stationary target was examined. Memory for a stationary target was displaced toward the landmark, and targets that were larger, further from, or above the landmark exhibited greater magnitudes of displacement. Displacement was generally larger when the landmark vanished prior to judgment than when the landmark was visible during judgment. Memory for stationary targets offset from the major vertical or horizontal cardinal axis of the landmark was also displaced toward that cardinal axis. The data support the hypotheses that spatial memory averaging of the locations of a target and landmark occurs, and that this averaging may be combined with representational gravity in determining the remembered position of a stationary target.

Humans↗

PubMed1999

Representational momentum in children: dynamic information and analogue representation.

Two groups of children and a control group of adults completed a visual memory task previously shown to produce representational momentum in adults. In the task, a computer-animated target was shown moving either horizontally or vertically, and the target vanished without warning. After the target vanished, observers indicated the location at which it had vanished. Both children and adults exhibited representational momentum, i.e., indicated locations slightly beyond where the target actually disappeared, and the magnitude of representational momentum was larger for younger children than adults. Implications of the results for issues of sensitivity to dynamics and for reliance on analogue representation are discussed.

Adult↗

PubMed1998

Some effects of representational friction, target size, and memory averaging on memory for vertically moving targets.

Observers viewed an animated ascending or descending target that varied in size and velocity across trials and appeared either (a) in isolation, (b) to slide along one side of a single larger stationary object, or (c) to slide between two larger stationary objects. Targets vanished without warning, and displacements (i.e., differences between actual and remembered final position) along the axis of motion and orthogonal axis were measured. Forward displacement (a) decreased with increases in implied friction, (b) increased with increases in target size for descending targets, and (c) decreased with increases in target size for ascending targets. When a larger stationary object was to one side of the target, orthogonal displacement was toward that object; when no object or objects on both sides were present, orthogonal displacement was near zero. Results are consistent with previous findings and speculation on the effects of representational friction, memory averaging, and target size on memory.

Analysis of Variance↗

PubMed1998

Listeners can discriminate among major chord positions.

Listeners judged whether two sequentially presented major chords were the same. When both chords were based on the same root, listeners discriminated between different chord positions, e.g., root position, first inversion, second inversion. The ability of listeners to discriminate between chord positions suggests that harmonic equivalence of different chord positions does not depend on perceptual equivalence and instead arises from a more cognitive representation.

Acoustic Stimulation↗

PubMed1996

The importance of a consideration of qualia to imagery and cognition.

Experiences of qualia, subjective sensory-like aspects of stimuli, are central to imagistic representation. Following Raffman (1993), qualia are considered to reflect experiential knowledge distinct from descriptive, abstract, and propositional knowledge; following Jackendoff (1987), objective neural activity is distinguished from subjective experience. It is argued that descriptive physical knowledge does not provide an adequate accounting of qualia, and philosophical scenarios such as the Turing test and the Chinese Room are adapted to demonstrate inadequacies of accounts of cognition that ignore subjective experience. Arguments by Dennett and others that qualia do not exist or that qualia do not provide additional explanatory power are addressed, and it is suggested that consideration of qualia is necessary in order to explain (and not just predict) objective behavior. The hypotheses of functional equivalence, second-order isomorphism, and psychophysical complementarity between imagery and perception are discussed, and the ability of analog and schematic models of imagery to account for qualia is examined.

Cognitive Science↗

PubMed1996

Displacement in depth: representational momentum and boundary extension.

Memory for targets moving in depth and for stationary targets was examined in five experiments. Memory for targets moving in depth was displaced behind the target with slower target velocities (longer ISIs and retention intervals) and beyond the target with faster target velocities (shorter ISIs and retention intervals), and the overall magnitude of forward displacement for motion in depth was less than the overall magnitude of forward displacement for motion in the picture plane. Memory for stationary targets was initially displaced away from the observer, but memory for smaller stationary targets was subsequently displaced toward the observer and memory for larger stationary targets was subsequently displaced away from the observer; memory for the top or bottom edge of a stationary target was displaced inside the target perimeter. The data are consistent with Freyd and Johnson's (1987) two-component model of the time course of representational momentum and with Intraub et al.'s (1992) two-component model of boundary extension.

Acceleration↗

PubMed1996

Representational momentum, centripetal force, and curvilinear impetus.

In 3 experiments, observers witnessed a target moving along a circular orbit and indicated the location at which the target vanished. The judged vanishing point was displaced forward in the direction of implied momentum and inward in the direction of implied centripetal force. In general, increases in either the angular velocity of the target or the radius length of the orbit increased the magnitude of forward displacement. If both angular velocity and radius length were varied, then increases in either angular velocity or radius length also increased the magnitude of inward displacement. The displacement patterns were consistent with hypotheses that analogues of momentum and centripetal force were incorporated into the representational system. A framework is proposed that accounts for (a) the forward and inward displacements and (b) naive-physics data on the spiral tube problem previously interpreted as suggesting a belief in a naive curvilinear-impetus principle.

Acceleration↗

PubMed1996

Synesthesia-like mappings of lightness, pitch, and melodic interval.

Synesthesia-like mappings between visual lightness and auditory pitch and between visual lightness and melodic interval were examined. When subjects rated how visual lightnesses and auditory pitches "fit together," lighter stimuli fit better with higher pitches, and darker stimuli fit better with lower pitches. These patterns were stronger against black than against white visual backgrounds; however, effects of visual background were eliminated when subjects had a large set of lightness levels from which to choose the visual lightness level that best fit a given auditory pitch or melodic interval. When subjects chose which visual lightness best fit or matched a melodic interval, lighter stimuli were chosen for ascending melodic intervals, and darker stimuli were chosen for descending melodic intervals. Larger melodic intervals produced more extreme (lighter or darker) choices. Auditory pitch exhibits meaningful synesthesia-like mappings with visual lightness when unidimensionally varied in frequency and when multidimensionally varied in interval size and direction.

Humans↗

PubMed1995

Cognitive representation of motion: evidence for friction and gravity analogues.

Five experiments examined whether judgments of the locations of horizontally moving targets were influenced by implied friction between the targets and larger stationary surfaces. When targets crashed through a barrier, forward displacement decreased. When targets slid along the upper or lower edge of a single surface, forward displacement decreased. When targets slid along the upper or lower edge of a single surface, forward displacement decreased; when targets slid between the upper and lower edges of different surfaces, forward displacement decreased further. Targets not in contact with a surface exhibited larger forward displacement with greater target velocities, but contact with a surface attenuated or reversed this pattern. When targets slid along the upper edge of a surface, downward displacement increased; when targets slid along the lower edge of a surface, downward displacement reversed. Downward displacements were larger for larger targets, especially after contact with a surface. The data suggest that target representations contain analogues to friction and gravity that influence remembered position.

Adult↗

PubMed1993

The effects of size, clutter, and complexity on vanishing-point distances in visual imagery.

The portrayal of vanishing-point distances in visual imagery was examined in six experiments. In all experiments, subjects formed visual images of squares, and the squares were to be oriented orthogonally to subjects' line of sight. The squares differed in their level of surface complexity, and were either undivided, divided into 4 equally sized smaller squares, or divided into 16 equally sized smaller squares. Squares also differed in stated referent size, and ranged from 3 in. to 128 ft along each side. After subjects had formed an image of a specified square, they transformed their image so that the square was portrayed to move away from them. Eventually, the imaged square was portrayed to be so far away that if it were any further away, it could not be identified. Subjects estimated the distance to the square that was portrayed in their image at that time, the vanishing-point distance, and the relationship between stated referent size and imaged vanishing-point distance was best described by a power function with an exponent less than 1. In general, there were trends for exponents (slopes on log axes) to increase slightly and for multiplicative constants (y intercepts on log axes) to decrease as surface complexity increased. No differences in exponents or in multiplicative constants were found when the vanishing-point was approached from either subthreshold or suprathreshold directions. When clutter in the form of additional imaged objects located to either side of the primary imaged object was added to the image, the exponent of the vanishing-point function increased slightly and the multiplicative constant decreased. The success of a power function (and the failure of the size-distance invariance hypothesis) in describing the vanishing-point distance function calls into question the notions (a) that a constant grain size exists in the imaginal visual field at a given location and (b) that grain size specifies a lower limit in the storage of information in visual images.

Adult↗

PubMed1993

Cross-modality matching in memory psychophysics: brightness and loudness.

Performance of subjects in tasks involving estimation of remembered magnitude and cross-modality matching of remembered magnitude for brightness and loudness stimuli was examined in two experiments. Subjects first learned nonsense syllable names associated with exemplars of five levels of brightness and exemplars of five levels of loudness. The stimuli were then removed and one of the nonsense syllable names was given by the experimenter. The subject formed an image of what the stimulus denoted by that name looked or sounded like and gave a judgment of remembered magnitude of that stimulus based upon the intensity portrayed in the image. In Exp. 1 subjects also completed a cross-modality matching task in which a stimulus in one dimension was shown, and subjects then estimated the magnitude that a stimulus in the other dimension would have to possess to match the intensity of the perceived stimulus. Performance was compared with that of a perceptual control group. In Exp. 2 subjects also completed a cross-modality matching task in which they were given the nonsense syllable name of a stimulus from one dimension, formed a vivid image of what the stimulus denoted by that name looked or sounded like, formed an image of a stimulus from the other dimension that possessed the same portrayed intensity as the named stimulus from the first dimension, and then estimated the intensity of the second (unnamed) stimulus. The power function offers an appropriate description of the responses on both the remembered magnitude and the cross-modality matching tasks. Implications for theories of imagery and psychophysics are discussed.

Adult↗

PubMed1993

The effect of context on visual representational momentum.

Effects of background context on representational momentum were examined in six experiments. In each experiment, three orientations of a target rectangle undergoing implied rotation (i.e., the inducing stimuli) were presented, and subjects judged whether the orientation of a fourth rectangle (i.e., the probe) was the same as or different from that of the third inducing stimulus. Target rectangles were enclosed within a larger square frame context during induction (i.e., presentation of the inducing stimuli), judgment (i.e., presentation of the probe), or both induction and judgment. If context during induction moved in the same direction as the inducing stimuli or if context during judgment was rotated slightly forward from the orientation of the final inducing stimulus, representational momentum was increased. If context during induction moved in the direction opposite to the inducing stimuli or if context during judgment was rotated slightly backward from the orientation of the final inducing stimulus, representational momentum was decreased or reversed. If context was present during both induction and judgment, direction of representational momentum was biased toward the context at judgment. Implications of context for accounts of representational momentum are discussed, and a tentative model is proposed.

Adult↗

PubMed1990

Cognitive representation of linear motion: possible direction and gravity effects in judged displacement.

The judged vanishing point of a target undergoing apparent motion in a horizontal, vertical, or oblique direction was examined. In Experiment 1, subjects indicated the vanishing point by positioning a crosshair. Judged vanishing point was displaced forward in the direction of motion, with the magnitude of displacement being largest for horizontal motion, intermediate for oblique motion, and smallest for vertical motion. In addition, the magnitude of displacement increased with faster apparent velocities. In Experiment 2, subjects judged whether a stationary probe presented after the moving target vanished was at the same location where the moving target vanished. Probes were located along the axis of motion, and probes located beyond the vanishing point evidenced a higher probability of a same response than did probes behind the vanishing point. In Experiment 3, subjects judged whether a stationary probe presented after the moving target vanished was located on a straight-line extension of the path of motion of the moving target. Probes below the path of motion evidenced a higher probability of a same response than did probes above the path of motion for horizontal and ascending oblique motion; probes above the path of motion evidenced a higher probability for a same response than did probes below the path of motion for descending oblique motion. Overall, the pattern of results suggests that the magnitude of displacement increases as proximity to a horizontal axis increases, and that in some conditions there may be a component analogous to a gravitational influence incorporated into the mental representation.

Adult↗

PubMed1989

Imagery, memory, and size-distance invariance.

The size-distance invariance hypothesis (SDIH) was examined for remembered and imaged stimuli. In Experiment 1, subjects gave remembered and imaged distances of familiar objects and imaged distance of nondescript rods. The relationship between stated size and distance is more adequately described by power functions with exponents less than 1 than by the more restricted SDIH (exponent of 1). In Experiment 2, subjects gave distance estimates to recalled and imaged familiar objects and described the visual context in which each object was situated. A different group then sorted the contexts into categories based on general similarity. There were no significant differences between distance estimates based on memory and those based on imagery, and the visual contexts were not sorted according to whether they were generated in the memory or in the imagery conditions. In Experiment 3, subjects estimated the distances to objects in an outdoor setting. A linear relationship was found between estimated and physical distance, suggesting that the lower exponents obtained in Experiments 1 and 2 were not artifacts of the distance judgment procedure.

Adult↗