The bigram trough hypothesis and the syllable number effect in lexical decision

There has been an increasing volume of evidence supporting the role of the syllable in various word processing tasks. It has, however, been suggested that syllable effects may be caused by orthographic redundancy. In particular, it has been proposed that the presence of bigram troughs at syllable boundaries cause what are seen as syllable effects. We investigated the bigram trough hypothesis as an explanation of the number of syllables effect for lexical decision in five-letter words and nonwords from the British Lexicon Project. The number of syllables made a significant contribution to prediction of lexical decision times along with word frequency and orthographic similarity. The presence of a bigram trough did not. For nonwords, the number of syllables made a significant contribution to prediction of lexical decision times only for nonwords with relatively long decision times. The presence of a bigram trough made no contribution. The evidence presented suggests that the bigram trough cannot be an explanation of the syllable number effect in lexical decision. A comparison of the results from words and nonwords is interpreted as providing some support for dual-route models of reading.     

Picture–word interference reveals inhibitory effects of syllable frequency on lexical selection

While previous research has shown that high syllable frequency can facilitate speech production at the level of phonological/phonetic encoding, little is known about its influence on prephonological processes, specifically lexical selection. The current study used a picture–word interference (PWI) task to (a) shed light on the stages of lexical access where syllable frequency is relevant, and (b) inform as to whether lexical selection is accomplished via competition among activated word options. Participants named pictures whose names had high-frequency (HF) and low-frequency (LF) first syllables while ignoring phonologically related (same first syllable) or unrelated distractor words that were presented simultaneously. Word frequency was also manipulated, as half of the targets were HF words, and half were LF words. Results revealed inhibitory syllable frequency effects in all conditions, such that targets with HF first syllables were named more slowly than targets with LF first syllables. However, inhibitory syllable frequency effects were exacerbated in conditions thought to reflect heightened lexical competition, specifically in the presence of phonologically related distractors and for targets with low word frequency. These findings reveal novel evidence for first-syllable frequency effects on lexical selection and offer further support for models proposing delays at lexical selection due to activation of nontarget competitors.     

Memory for Movement in Blind Children

The author assessed the mechanisms underlying skilled production of keying sequences in the discrete sequence-production task by examining the effect of sequence length on mean element execution rate (i.e., the rate effect). To that end, participants (N = 9) practiced fixed movement sequences consisting of 2, 4, and 6 key presses for a total of 588 trials per sequence. In the subsequent test phase, the sequences were executed with and without a verbal short-term memory task in both simple and choice reaction time (RT) paradigms. The rate effect was obtained in the discrete sequence-production task—including the typical quadratic increase in sequence execution time (SET, which excludes RT) with sequence length. The rate effect resulted primarily from 6-key sequences that included 1 or 2 relatively slow elements at individually different serial positions. Slowing of the depression of the 2nd response key (R₂) in the 2-key sequence reduced the rate effect in the memory task condition, and faster execution of the 1st few elements in each sequence amplified the rate effect in simple RT. Last, the time to respond to random cues increased with position, suggesting that the mechanisms that underlie the rate effect in new sequences and in familiar sequences are different. The data were in line with the notion that coding of longer keying sequences involves motor chunks for the individual sequence segments and information on how those motor chunks are to be concatenated.     

Interference Effects in Learning Similar Sequences of Discrete Movements

Three experiments were conducted to examine proactive and retroactive interference effects in learning 2 similar sequences of discrete movements. In each experiment, the participants in the experimental group practiced 2 movement sequences on consecutive days (1 on each day, order counterbalanced across participants) followed by retention tests on the third day. In all, 2 out of 8 target locations differed between the 2 sequences. Experiment 1 established the nature of the interference effects in the present setup. Clear evidence was found for button-specific proactive and retroactive interference effects. Experiments 2 and 3 further probed the mechanisms underlying those effects, by varying the numbers of repetitions (50 or 250) of the 1st and 2nd sequence (Experiment 2) and the hand, dominant or nondominant, with which the sequences were practiced (Experiment 3). Experiment 2 showed that after a mere 50 repetitions, the representation of the movement structure was strong enough to evoke the effects observed in Experiment 1. Experiment 3 revealed that learning with the dominant hand did not result in more pronounced interference effects compared with learning with the nondominant hand. In combination, these results suggest that changes in the representation of the movement structure are primarily responsible for the observed interference effects.     

An analysis of stimuli that influence compliance during the high-probability instruction sequence

When we evaluated variables that influence the effectiveness of the high-probability (high-p) instruction sequence, the sequence was associated with a precipitous decrease in compliance with high-p instructions for 1 participant, thereby precluding continued use of the sequence. We investigated the reasons for this decrease. Stimuli associated with the low-p instruction were systematically added and removed in the context of the high-p instructions, and results suggest that the stimuli associated with the low-p instruction influenced compliance with the high-p instructions.     

The contribution of prefixes to morphological processing of Spanish words

Three series of priming experiments were conducted to probe the morphological and phonological contributions to visual word recognition in Spanish. Prefixed, e.g., INCAPAZ (incapable), and pseudoprefixed, e.g., INDUSTRIA (industry) target words were presented for recognition following a prefixed, e.g., infeliz (unhappy), or pseudoprefixed, e.g., insulto (insult), prime starting with the same syllable as the target, at masked short or long stimulus onset asynchronies (SOAs). At long SOAs the recognition of prefixed targets was facilitated by prefixed primes and inhibited by pseudoprefixed ones, whereas both prefixed and pseudoprefixed primes facilitated the recognition at short SOAs. In contrast, the recognition of pseudoprefixed targets was unaffected by the kind of prime presented, even when we used pairs of words overlapping in syllables that cannot be prefixes in Spanish. These results support a special status for morphological elements in access to meaning in reading.     

Retention of Implicit Sequence Learning in Persons Who Stutter and Persons With Parkinson's Disease

ABSTRACT. The authors investigated the retention of implicit sequence learning in 14 persons with Parkinson's disease (PPD), 14 persons who stutter (PWS), and 14 control participants. Participants completed a nonsense syllable serial reaction time task in a 120-min session. Participants named aloud 4 syllables in response to 4 visual stimuli. The syllables formed a repeating 8-item sequence not made known to participants. After 1 week, participants completed a 60-min retention session that included an explicit learning questionnaire and a sequence generation task. PPD showed retention of general learning equivalent to controls but PWS's reaction times were significantly slower on early trials of the retention test relative to other groups. Controls showed implicit learning during the initial session that was retained on the retention test. In contrast, PPD and PWS did not demonstrate significant implicit learning until the retention test suggesting intact, but delayed, learning and retention of implicit sequencing skills. All groups demonstrated similar limited explicit sequence knowledge. Performance differences between PWS and PPD relative to controls during the initial session and on early retention trials indicated possible dysfunction of the cortico-striato-thalamo-cortical loop. The etiological implications for stuttering, and clinical implications for both populations, of this dysfunction are discussed.     

The Lateral Coding of Rotations

A number of experimental studies have consistently shown the locus of spatial S-R compatibility effects to be the selection of the response within an abstract memory code. The purpose of the present study was to test, in the particular case of wheel rotations, the general proposition that any response that a subject internally codes in terms of left and right may be interfered with by the lateral location of the stimuli in a Simon paradigm. Experiment 1 showed that the auditory Simon effect occurred in a task where the subjects had to rotate a steering wheel bimanually either clockwise or counterclockwise according to sound pitch, despite the fact that responses of this kind are undefined with respect to laterality. Experiment 2 confirmed this result in a unimanual rotation condition and suggested that the ear-rotation compatibility effect may be added to the effect of a biomechanical factor, pronation versus supination, supporting the idea of an abstract motor code. In Experiment 3, subjects rotated the steering wheel with their hands on the lowest part of the wheel. When the response movement made the spot of a C.R.T. move laterally in accordance with the performed rotation, the subjects coded their response directly in terms of its effect on the visual display. For subjects not receiving visual feedback, no compatibility effect occurred. However, the individual data were compatible with the notion that some subjects in this group coded their responses in terms of wheel rotations, and others in terms of hand movements.     

析其数之理,赏其序之美--今本《周易》卦序排列数学规律再探

今本《周易》卦序是一篇精美绝伦的古典作品,其思想之深刻耐人寻味,其数理之精妙绝无仅有,其设计之完美令人叹为观止。《序卦》卦序的排列蕴含多重数理原则,本文将对一阴五阳卦分布律、二阳四阴卦分布律、三阴三阳卦分布律进行更精密地刻画以期对其认识更臻完善。而十二辟卦分布律、上经十八卦容斥律和下经十八卦容斥律的发现,更使我们有理由相信,《序卦》卦序是古人高超的数学才华的集中体现,是一件隐身数千年的数学极品。     

Using a High Probability Command Sequence to Increase Classroom Compliance: The Role of Behavioral Momentum

One of the most problematic behaviors in children with developmental disabilities is noncompliance. Although behavioral research has provided strategies to impact noncompliance, oftentimes the methodologies are consequent techniques, which may not be conducive to implementation by the classroom teacher. In this teacher-designed and implemented study, a sequence of high-probability instructional commands preceded the targeted low-probability command, in an attempt to increase compliance to the low-probability command. Results, discussed within the body of behavioral momentum research, showed an increase in compliance to low-probability classroom commands for a seven year-old student with moderate mental retardation and Down Syndrome. Results are discussed as (a) an effective, antecedent approach to classroom compliance and (b) re-connecting the gap between applied behavioral research and experimentally controlled classroom practice.