Most current models of word naming are restricted to processing monosyllabic words and pseudowords. This limitation stems from difficulties in representing the orthographic and phonological codes for words varying substantially in length. Sibley, Kello, Plaut, and Elman (2008) described an extension of the simple recurrent network architecture, called the sequence encoder, that learned orthographic and phonological representations of variable-length words. The present research explored the use of sequence encoders in models of monosyllabic and bisyllabic word naming. Performance in these models is comparable to other models in terms of word and pseudoword naming accuracy, as well as accounting for naming latency phenomena. Although the models do not address all naming phenomena, the results suggest that sequence encoders can learn orthographic and phonological representations, making it easier to create models that scale up to larger vocabularies, while accounting for behavioural data.
Using straight translatory motion of a visual peripheral cue in the frontoparallel plane, and probing target discrimination at different positions along the cue's motion trajectory, we found that target orientation discrimination was slower for targets presented at or near the position of motion onset (4.2 degrees off centre), relative to the onset of a static cue (Experiment 1), and relative to targets presented further along the motion trajectory (Experiments 1 and 2). Target discrimination was equally fast and accurate in the moving cue conditions relative to static cue conditions at positions further along the cue's motion trajectory (Experiment 1). Moreover, target orientation discrimination was not slowed at the same position, once this position was no longer the motion onset position (Experiment 3), and performance in a target colour-discrimination task was not slowed even at motion onset (Experiment 4). Finally, we found that the onset location of the motion cue was perceived as being shifted in the direction of the cue's motion (Experiment 5). These results indicate that attention cannot be as quickly or precisely shifted to the onset of a motion stimulus as to other positions on a stimulus' motion trajectory.
Classic connectionist models of reading have traditionally focused on English, a language with a quasiregular (deep) relationship between orthography and phonology, and very little work has been conducted on more transparent (shallow) orthographies. This paper introduces a parallel distributed processing (PDP) model of reading for Italian. The model was explicitly developed in order to deal with polysyllabic words and stress assignment. One of the core issues regarding such PDP models is whether they can show sensitivity to large grain sizes, as documented by the existence of morphological and neighbourhood effects in nonword reading aloud showed by native Italian speakers (Arduino Burani, 2004; Burani, Marcolini, de Luca, Zoccolotti, 2008). The model is successful in simulating these effects, previously accounted for by dual route architectures. The model was also able to simulate stress consistency effects.
This study investigated beginning adult second language (L2) learners' sensitivity to L2 morphosyntactic violations as a function of cross-language similarity. Online sensitivity was indexed by self-paced reading times at: (1) the critical word at which the violation could first be detected, (2) the post-critical word, and (3) the sentence-final word. In conditions in which morphosyntactic marking systems were similar or different in L1 and L2, reading times on the critical word were slower when it cued a violation than when it did not; however, this sensitivity was not apparent in a construction unique to L2. Slower reading times to violations spilled over onto the post-critical word. Cross-language similarity also influenced sentence-final word reading times. Despite this online sensitivity, post-sentence grammaticality judgements were generally poor. However, these judgements were influenced by morphosyntactic markings on words after the critical word, suggesting that learners can make use of this information.
It has been suggested that when words and nonwords are presented mixed in the same blocks in transparent scripts the word frequency effect can be eliminated. This is either because in reading mixed blocks the lexical route is deemphasised in favour of the nonlexical route (route deemphasis) or because a homogenisation of reaction times occurs for words and nonwords by adjustment of a time criterion for articulation (time criterion). In five experiments using different list manipulations and experimental designs, we assessed the effects of frequency and length in reading aloud words and nonwords in the Italian transparent orthography. The effect of word frequency remained constant irrespective of context manipulation and nonword characteristics. As reading nonwords may be easier in Italian than in English, control over reading processing may be unnecessary for Italian readers. The results are discussed with respect to current computational models of reading.
Perceptual load hypothesis is proposed as a compromise between early and late theory of selective attention which states that the selection will operate early when the load on perception is high and it will operate late when the load on perception is low. Experimental findings have shown that the perceptual load hypothesis is too simplistic in nature as perceptual load is not the only determinant of selection processes. It is difficult to apply the load hypothesis to explain the occurrence of early selection in low load displays as well as the selection processes that operate on distractor and target stimuli that are a part of the same object. Factors like spatial proximity, cues that manipulate the spatial extent of attentional focus, salience of targets as well as the distractors, and perceptual grouping between the target and the distractors should be taken into account while explaining the selective control of attention. Thus, the perceptual load of the display is one such factor that affects selective attention and goal-directed behaviour, but it is not the only factor to affect the selective control of attention.
Unexpected sounds have been shown to capture attention, triggering an orienting response. However, opposing effects of this attention capture on the performance of a concomitant visual task have been reported, in some instances leading to distraction and in others to facilitation. Moreover, the orienting response towards the unexpected stimuli can be modulated by working memory (WM) load, but the direction of this modulation has been another issue of controversy. In four experiments, we aimed to establish the critical factors that determine whether novel sounds facilitate or disrupt task performance and the modulation of these effects by WM load. Depending on the overall attentional demands of the task, novel sounds led to faster or slower responses. WM load attenuated novel sound effects, independent of their direction (facilitation or distraction). We propose a model by which the unexpected stimuli always generate the same orienting response but result in distraction or facilitation depending critically on the attentional focusing induced by the task at hand and the temporal relationship between the irrelevant and task-related stimuli.
Previous research on recognising action features from point-light displays (PLDs) has focused on cues linked directly to the observed action. This paper presents two experiments examining the feasibility of predicting nonvisible movement outcomes from PLDs. A total of 127 sports students aged 19-37 years compared the distances of two throws in boules with masked ball flight. In Experiment 1, models were depicted as either full or reduced (only arm) PLDs and contrasted with a video condition. Results showed no differences between conditions, but better discrimination performance for larger differences between throwing distances. Experiment 2 reduced information even further. Both a reduction of PLDs to one point representing the hand and a reduction of the time course of the arm up to the point of ball release had detrimental effects on discrimination performance. Results are discussed in relation to concepts postulating the use of motor representations for movement observation.
Concurrent tasks, such as articulatory suppression and manual tapping, are used to understand the mechanisms underlying short-term memory by overloading domain-specific resources. The present study addresses the debate regarding the theoretical frameworks accounting for interference in serial recall by comparing the effects of both the modality of concurrent tasks (verbal vs. spatial) as well as the state of the tasks (steady vs. changing) in both verbal and spatial recall. The findings indicate that the verbal changing-state concurrent task significantly impaired digit recall, whereas the spatial changing-state concurrent task significantly impaired block recall. The theoretical implications are discussed in the context of a multimodal working memory model with domain-specific resources and a unitary approach to short-term memory.
Two cross-modal lexical decision experiments investigated the role of the length of the idiom string (Experiment 1) and of prior sentential context (Experiment 2) in spoken idiom recognition. The idiomatic meaning was activated at the offset of long idioms but not of short idioms when the idiom was preceded by a neutral context. The idiomatic meaning of short idioms was instead activated at the string offset when the idiom was preceded by an idiomatic context. The results support the Configuration Hypothesis (Cacciari & Tabossi, 1988).
The interference in colour naming may extend beyond critical Stroop trials. This "slow'' effect was first discovered in emotional Stroop tasks, but is extended here to classical Stroop. In two experiments, meaningless coloured letter strings followed a colour word or neutral word. Student participants (Experiment 1), and 18 stroke patients and 18 matched controls (Experiment 2) showed substantial interference by incongruent colour words, both in the word trial (fast component) and in the subsequent string trial (slow component). Different patient subgroups emerged from the comparison of Stroop performance with the controls. An association of fast and slow components was only found in one subgroup. Exploratory analyses revealed no clear differences in damage location between subgroups. Fast interference caused by colour-meaning conflict may be specific for classical Stroop, but the broader occurrence of slow effects suggests a more generalised process of disengagement from attention-demanding stimuli.
The present study examined the effect of visual feedback on the ability to recognise and consolidate pitch information. We trained two groups of nonmusicians to play a piano piece by ear, having one group receiving uninterrupted audiovisual feedback, while allowing the other only to hear, but not see their hand on the keyboard. Results indicate that subjects for whom visual information was deprived showed significantly poorer ability to recognise pitches from the musical piece they had learned. These results are interesting since pitch recognition ability would not intuitively seem to rely on visual feedback. In addition, we show that subjects with previous experience in computer touch-typing made fewer errors during training when trained with no visual feedback, but did not show improved pitch recognition ability posttraining. Our results demonstrate how sensory redundancy increases robustness of learning, and further encourage the use of audiovisual training procedures for facilitating the learning of new skills.
Miller and Paredes (1990) found that both children's and adults' performance of simple addition and multiplication tested in mixed-operation blocks was slower and more susceptible to operation errors (e.g., 6 + 2=12 or 6x2=8) compared to pure-operation blocks; but mixed-operation costs were greater for addition than for multiplication. We pursued the source of these effects in adults (n=96) by examining effects of operation switching and cueing. We replicated the asymmetrical costs of mixing addition and multiplication and demonstrated that these owed, in part, to asymmetrical task switching costs. Operation foreknowledge (a visual cue appearing 2 s before the problem) moderated both mixing and switch costs. This suggests that an asymmetry between addition and multiplication in the utility of preparation contributed to asymmetric mixing costs. Miller and Paredes proposed that the asymmetric costs of mixing operations observed in adults echoed an asymmetry developed in childhood when multiplication is initially learned. This might be correct, but our results raise the possibility that the asymmetry reflects operation-specific costs and interference effects that arise during the experiment.
Numerals are processed by a phylogenetically old analogue magnitude system. Can culturally new negative numerals be processed using this same representation? To find out whether magnitude representation could be used, we contrasted three possible processing mechanisms: an extended magnitude system for both positive and negative numbers, a mirroring mechanism that could transform negative values to the positive range to be processed on the positive magnitude system, and a sign shortcut strategy that can process the signs of numbers independently of the absolute values of numerals. To test these three hypotheses, a comparison task was used and the reaction time pattern, numerical distance, and Spatial-Numerical Association of Response Codes (SNARC) effect was analysed. The results revealed a mirroring process along with a sign shortcut mechanism. The SNARC effect was observed only when positive numbers were compared.
Nonword reading performance, that is, the ability to generate plausible pronunciations to novel items, has probably been the hardest test case for computational models of reading aloud. This is an area where rule-based models, such as the Dual-Route Cascaded (DRC) model, typically outperformed connectionist learning models. However, what is the evidence that people apply rules when reading nonwords? This was investigated in German. Nonwords were created that allowed us to test whether people apply an abstract rule to determine vowel length or whether they would be sensitive to the statistical distribution of vowel length in the mental lexicon. The human data showed a great amount of variability in nonword pronunciations. Simulations of these nonwords, where the DRC was contrasted with a fully implemented and freely available German version of the connectionist dual process model (German_CDP+), a model that learns the statistical mapping between spelling and sound, showed that CDP+ provided a better account of the data than the DRC. These results support the view that rule based models may simply approximate patterns of language use rather than provide an accurate description of the underlying cognitive machinery.
The study of two-digit numbers processing has recently gathered a growing interest. Here, we examine whether differences at encoding of two-digit oral verbal numerals induce differences in the type of processing involved. Twenty-four participants were submitted to a comparison task to 55. Differences at encoding were introduced by the use of dichotic listening and synchronous (synchronous condition) or asynchronous presentation (tens-first and units-first conditions) of the two-digit numerals' components. Our results showed that differences at the encoding stage of two-digit numerals involve: (1) different comparison processes (tens-first and units-first conditions: parallel comparison; synchronous condition: parallel and holistic comparison); and (2) differences in the weight of the tens-and units-effects. Therefore, attentional mechanisms determining at the encoding stage how much attention is paid to the two-digit numerals' components might account for the different types of processing found with two-digit numbers.
Recent research has demonstrated that proactive interference (PI) between the names of familiar individuals in a memory task is category specific, and that subsequent release from proactive interference (RPI) is a useful tool for investigating the underlying categorisation of memory for people. These RPI effects are in line with the influential Interactive Activation and Competition (IAC) model of person recognition, which predicts the existence of such categorical effects. Here we report an experiment precisely replicating the categorical PI and RPI effects found previously for occupational categories, but using faces instead of names as stimuli. The results underscore the use of PI as a tool to investigate semantic categorisation, are compatible with models proposing a single point of access to semantic information about people and provide further evidence for the categorical organisation of person knowledge.
How fast can information of a first target (T1) in a rapid serial visual presentation be used for top-down allocation of attention in time? A valid cue about the temporal position of a second target (T2) was integrated into T1. The data show that 100 ms after T1 onset, T2 was identified better than without cue, raising the conditional T2 performance. T1 apparently triggers a facilitative effect of attention, known from other paradigms such as peripheral cueing.
The temporal reproduction task is often used to investigate inter-individual differences in the ability to perceive time without any further analyses of the contribution of motor responses to temporal performance. The present study examined the role of motor responses in the reproduction of a 2.5 s and a 4.5 s signal duration in children and adults, with the former producing longer motor responses. The results showed that the 2.5 s duration was overestimated, especially by the younger children, whereas the 4.5 s duration was underestimated in all age groups. Further analyses indicated that the developmental differences related to motor response time explained the age-related difference in temporal reproduction for the shorter duration but not for the longer duration. The modelling of our data suggests that, for the shorter signal duration, the children initiated their responses at the same time as the adults, but that they reproduced longer durations because their motor response took more time to complete. In contrast, for the 4.5 s duration, the children initiated their responses earlier than the adults. However, they reproduced duration values close to the target time because their motor responses took longer. In addition, whatever the duration value to be reproduced, the representation of the sample duration was more variable in the younger children.
