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P Bertelson

Publications and source records attributed to P Bertelson.

At least 19 recordsLinked to original sources
PubMed2001

Directing spatial attention towards the illusory location of a ventriloquized sound.

In this study, we examined whether ventriloquism can rearrange external space on which spatial reflexive attention operates. The task was to judge the elevation (up vs down) of auditory targets delivered in the left or the right periphery, taking no account of side of presentation. Targets were preceded by either auditory, visual, or audiovisual cues to that side. Auditory, but not visual cues had an effect on the speed of auditory target discrimination. On the other hand, a ventriloquized cue, consisting of a tone in central location synchronized with a light flash in the periphery, facilitated responses to targets appearing on the same side as the flash. That effect presumably resulted from the attraction of the apparent location of the tone towards the flash, a well-known manifestation of ventriloquism. Ventriloquism thus can reorganize space in which reflexive attention operates.

Adult↗
PubMed2001

The ventriloquist effect does not depend on the direction of automatic visual attention.

Previously, we showed that the visual bias of auditory sound location, or ventriloquism, does not depend on the direction of deliberate, or endogenous, attention (Bertelson, Vroomen, de Gelder, & Driver, 2000). In the present study, a similar question concerning automatic, or exogenous, attention was examined. The experimental manipulation was based on the fact that exogenous visual attention can be attracted toward a singleton--that is, an item different on some dimension from all other items presented simultaneously. A display was used that consisted of a row of four bright squares with one square, in either the left- or the rightmost position, smaller than the others, serving as the singleton. In Experiment 1, subjects made dichotomous left-right judgments concerning sound bursts, whose successive locations were controlled by a psychophysical staircase procedure and which were presented in synchrony with a display with the singleton either left or right. Results showed that the apparent location of the sound was attracted not toward the singleton, but instead toward the big squares at the opposite end of the display. Experiment 2 was run to check that the singleton effectively attracted exogenous attention. The task was to discriminate target letters presented either on the singleton or on the opposite big square. Performance deteriorated when the target was on the big square opposite the singleton, in comparison with control trials with no singleton, thus showing that the singleton attracted attention away from the target location. In Experiment 3, localization and discrimination trials were mixed randomly so as to control for potential differences in subjects' strategies in the two preceding experiments. Results were as before, showing that the singleton attracted attention, whereas sound localization was shifted away from the singleton. Ventriloquism can thus be dissociated from exogenous visual attention and appears to reflect sensory interactions with little role for the direction of visual spatial attention.

Adult↗
PubMed2000

Ventriloquism in patients with unilateral visual neglect.

Can visual stimuli that go undetected, because they are presented in the extinguished region of neglect patients' visual field, nevertheless shift in their direction the apparent location of simultaneous sounds (the well-known 'ventriloquist effect')? This issue was examined using a situation in which each trial involved the simultaneous presentation of a tone over loudspeakers, together with a bright square area on either the left, the right or both sides of fixation. Participants were required to report the presence of squares, and indicate by hand pointing the apparent location of the tone. Five patients with left hemineglect consistently failed to detect the left square, either presented alone or together with another square on the right. Nevertheless, on bimodal trials with a single undetected square to the left, their sound localization was significantly shifted in the direction of that undetected square. By contrast, in bimodal trials with either a single square on the right or a square on each side, their sound localization showed only small and non-significant shifts. This particular result might be due to a combination of low discrimination of lateral sound deviations with variable individual strategies triggered by conscious detection of the right square. The important finding is the crossmodal bias produced by the undetected left visual distractors. It provides a new example of implicit processing of inputs affected by unilateral visual neglect, and on the other hand is consistent with earlier demonstrations of the automaticity of crossmodal bias.

Aged↗
PubMed2000

The ventriloquist effect does not depend on the direction of deliberate visual attention.

It is well known that discrepancies in the location of synchronized auditory and visual events can lead to mislocalizations of the auditory source, so-called ventriloquism. In two experiments, we tested whether such cross-modal influences on auditory localization depend on deliberate visual attention to the biasing visual event. In Experiment 1, subjects pointed to the apparent source of sounds in the presence or absence of a synchronous peripheral flash. They also monitored for target visual events, either at the location of the peripheral flash or in a central location. Auditory localization was attracted toward the synchronous peripheral flash, but this was unaffected by where deliberate visual attention was directed in the monitoring task. In Experiment 2, bilateral flashes were presented in synchrony with each sound, to provide competing visual attractors. When these visual events were equally salient on the two sides, auditory localization was unaffected by which side subjects monitored for visual targets. When one flash was larger than the other, auditory localization was slightly but reliably attracted toward it, but again regardless of where visual monitoring was required. We conclude that ventriloquism largely reflects automatic sensory interactions, with little or no role for deliberate spatial attention.

Adult↗
PubMed1997

Explicit speech segmentation and syllabic onset structure: developmental trends.

Recent applications of the hierarchical theory of the syllable to the development of explicit speech segmentation are critically examined. One particular prediction, that an initial consonant is more easily isolated when it constitutes the complete onset of a syllable than when it is part of a cluster onset, was tested on children with grade levels ranging from kindergarten to second grade. At each level, two independent groups of children worked with either CVCC (first consonant complete onset) or CCVC (part of cluster onset) syllables. First- and second-graders performed better on the CVCC than on the CCVC material in an initial consonant deletion task, but not when the task was comparison on the basis of that consonant. With the same instructions as the older children, kindergarten children performed at floor level on both tasks with both materials. However, in a new experiment in which the deletion task was presented as a puppet game, and with pretraining and selection on vowel deletion, a significantly higher level of success was achieved by the children working with the CVCC material. These results are consistent with the notion of developmental precedence of onset segmentation on phoneme segmentation. On the other hand, the results of the first and second graders show that onset superiority is not specific for the pre-reading stage.

Child↗
PubMed1993

The effects of alphabetic-reading competence on language representation in bilingual Chinese subjects.

The metaphonological abilities of two groups of bilingual Chinese adults residing in the Netherlands were examined. All subjects were able to read Chinese logograms, but those in the alphabetic group had, unlike those in the non-alphabetic group, also acquired some competence in reading Dutch. In Experiment 1, strong, significant differences between the two groups were obtained in the task of deleting the initial consonant of a Dutch spoken pseudo-word and also in a task consisting of segmenting a sentence into progressively smaller fragments, but there was no difference in a rhyme--nonrhyme classification task with pairs of Dutch words. In the latter task, the subjects in the two groups performed at a near-ceiling level. In Experiment 2, a significant difference was obtained again for the consonant-deletion task and no difference with an initial syllabic-vowel-deletion task, but the non-alphabetic subjects performed at a significantly lower level than the alphabetic subjects in the rhyme-judgement task. Taken together, these results are consistent with the earlier evidence that learning a non-alphabetic orthography does not promote awareness of the segmental structure of utterances. On the other hand, they confirm, for a population of Chinese readers, the conclusion drawn earlier from work with illiterate subjects that explicit instruction is more critical for the development of segmental representations of language than of representations of higher levels such as those of rhymes and syllables.

Adolescent↗
PubMed1992

Finger movements in braille reading: the effect of local ambiguity.

The hand movements of blind readers were recorded while they read sentences containing temporary local ambiguities, designed to induce garden path effects upon disambiguation. A syntactically ambiguous beginning ("The spy saw the cop with ... ") was compatible with attachment of the following prepositional phrase (PP) either to the verb ("saw") or the noun ("cop"), but the content of the PP was inconsistent with verb phrase attachment in NPA sentences ("with a revolver"), not in VPA sentences ("with binoculars"). Mean total scanning time per character increased in the PP region of NPA sentences, not of VPA sentences. The effect, however, depended on both the content of the PP and its predictability, and was significant by items only when both factors favoured VPA. The slowing down over the PP was entirely due to increased incidence of regressions to that region, and first-pass scanning speed was unaffected by sentence type. In studies with visual reading, disambiguation has been found to have a large effect on first-pass scanning. The results confirm previous suggestions that regressions are the main repair device available to the braille reader to cope with local increases in processing load.

Adult↗
PubMed1992

The time course of Braille word recognition.

Skilled blind readers read French nouns with the uniqueness point in different locations, presented in unabbreviated braille, and either pronounced each item (Experiment 1) or classified it as to gender (Experiments 1-3). As in previous studies with spoken words, effects of uniqueness point location on recognition reaction time were taken as demonstrating on-line lexical access. For braille words, significant effects were obtained in Experiment 1 in the two tasks. In Experiment 2, blind Ss demonstrated comparable relative uniqueness point effects for gender classification of braille and of spoken words, showing that on-line lexical access is not specific to speech. Experiment 3 showed that the effect of uniqueness point location is limited to the higher frequency words. Finally, mean finger scanning speed did not differ between the pre- and post-uniqueness point regions of the words.

Adult↗
PubMed1989

The effect of the uniqueness point in spoken-word recognition.

The study examines the possibility of observing on-line recognition of spoken words through manipulations of the location of the uniqueness point (UP) in a gender-classification task. The subjects were presented with spoken French nouns and had to indicate by a key-press response whether each was feminine or masculine. RTs measured from word onset were significantly correlated with UP location, a finding that supports the notion of online processing. The effect of UP location is, however, smaller than that predicted by the original cohort theory (that recognition occurs exactly at the UP). On the other hand, it is stronger when words with respectively early and late UPs are presented in homogeneous blocks rather than in mixed order. It is proposed that the results can be accounted for by the notion of a sub-optimal lexical strategy in which some monitoring of the phonetic data continues past the UP.

Adult↗
PubMed1989

Simultaneous reading of braille with the two hands: reply to Millar (1987).

Millar (1987) argues that when braille readers scan a passage of text with the two hands side by side, the reading fingers actually alternate contacts with the letters. Reanalysis of her data shows that they provide little support for that claim. On the other hand, unlike a majority of the subjects studied by Bertelson et al. (1985), Millar's subjects do apparently not engage in simultaneous exploration of the end of one line and the beginning of the next one by different fingers. The suggestion offered by Millar that our findings result from an inadequate analysis of the data is rejected. The difference between the two sets of data should for the time being be considered as reflecting genuine differences between the populations that were sampled in the two studies.

Blindness↗
PubMed1987

Spatial constraints on attention to speech in the blind.

When sighted persons try to identify one of two speech utterances coming from different directions, they display both a frontal position advantage, i.e., better recognition of inputs from the front than of those from the rear, and a right-side advantage, better recognition of inputs from the right than of those from the left. The present study demonstrates a dissociation of the two effects in blind subjects (N = 10) who showed no frontal position advantage together with a right-side advantage superior to that of control sighted subjects (N = 16). There was no systematic difference between congenitally blind subjects and noncongenitals. The absence of frontal position advantage in the blind is consistent with the notion that this effect originates in the habit of sighted listeners to orient toward the source of heard speech. The occurrence of at least normal right-side advantage in the blind does not support recent suggestions of reduced lateralization of language functions in such subjects.

Adolescent↗
PubMed1987

Shifting ear differences in melody recognition through strategy inducement.

In a previous study, the pattern of ear superiority displayed by nonmusicians in a task where dichotically presented target melodies have to be recognized among four probes was found to be correlated with subjects' descriptions of their operating modes: those who reported focusing on critical local differences in pitch tended to show right ear advantage (REA) and the others LEA. The purpose of the present study was to examine if laterality patterns can be affected by treatments designed to induce particular strategies. Treatments supposed to orient toward analytic processing, advising attention to critical notes, with (Experiment 2) or without (Experiment 1) the additional task of reporting their location, produced the expected shift toward REA. To the contrary, treatments supposed to orient toward holistic processing, advising attention to overall contour or requesting aesthetic judgments (Experiment 1), failed to produce the expected shift toward LEA. The result can be attributed either to a basic difference in susceptibility to strategic control between the different operating modes or, more simply, to ineffectiveness of the present holistically oriented treatments.

Adolescent↗