Effects of targets embedded within words in a visual search task

Visual search performance can be negatively affected when both targets and distracters share a dimension relevant to the task. This study examined if visual search performance would be influenced by distracters that affect a dimension irrelevant from the task. In Experiment 1 within the letter string of a letter search task, target letters were embedded within a word. Experiment 2 compared targets embedded in words to targets embedded in nonwords. Experiment 3 compared targets embedded in words to a condition in which a word was present in a letter string, but the target letter, although in the letter string, was not embedded within the word. The results showed that visual search performance was negatively affected when a target appeared within a high frequency word. These results suggest that the interaction and effectiveness of distracters is not merely dependent upon common features of the target and distracters, but can be affected by word frequency (a dimension not related to the task demands).     

Parameters affecting the maintenance of negatively reinforced key pecking

Three negative reinforcement experiments employing a key-peck response are described. In Experiment I, pigeons shocked on the average of twice per minute (imposed condition) could produce, by pecking a key, an alternate condition with correlated stimuli. Delayed shocks were added, across sessions, to the alternate condition until pecking stopped. Two of three pigeons continued to peck despite a 100% increase in shock frequency. In Experiment II, pigeons were shocked in the imposed condition four times per minute. The postresponse delay to shock was held constant by delivering, in the alternate condition, the next shock, or the next two, three, or four shocks from the imposed-condition shock schedule. All three subjects continued to peck with no change in delay to the first two postresponse shocks but with a 75% reduction in shock frequency. In Experiment III, a response produced an immediate shock followed by a shock-free period. Three of four subjects continued to respond despite reduced delay to shock. Delay-to-shock or shock-frequency reduction was sufficient to maintain key pecking, but neither was necessary. The conditions that negatively reinforce the pigeon's key peck were similar to conditions that negatively reinforce the rat's bar press.     

Schedule-induced drinking as a function of interreinforcement interval in the rhesus monkey

Lever presses by two rhesus monkeys produced food pellets that were assigned by both an ascending and descending series of fixed-interval schedules whose values varied between 1 and 512 sec. The amount of schedule-induced drinking was bitonically related to interreinforcement interval, reaching a maximum at approximately 120 sec and declining at longer fixed intervals. The relation between water intake and interreinforcement interval was complexly related to two drinking measures: (1) the probability of drinking following a pellet and (2) the amount drunk per bout. Drinking rate was also bitonically related to interreinforcement interval.     

Use of phonetic specificity during the acquisition of new words: differences between consonants and vowels

The present study explores the issue of the use of phonetic specificity in the process of learning new words at 20 months of age. The procedure used follows Nazzi and Gopnik [Nazzi, T., & Gopnik, A. (2001). Linguistic and cognitive abilities in infancy: When does language become a tool for categorization? Cognition, 80, B11-B20]. Infants were first presented with triads of perceptually dissimilar objects, which were given made-up names, two of the objects receiving the same name. Then, word learning was evaluated through object selection/categorization. Tests involved phonetically different words (e.g. [pize] vs. [mora], Experiment 1), words differing minimally on their onset consonant (e.g. [pize] vs. [tize], Experiment 2a), and conditions which had never been tested before: non-initial consonantal contrasts (e.g. [pide] vs. [pige], Experiment 2b), and vocalic contrasts (e.g. [pize] vs. [pyze]; [pize] vs. [paze]; [pize] vs. [pizu], Experiments 3a-c). Results differed across conditions: words could be easily learnt in the phonetically different condition, and were learnt, though to a lesser degree, in both the initial and non-initial minimal consonant contrast; however, infants' global performance on all three vocalic contrasts was at chance level. The present results shed new light regarding the specificity of early words, and raise the possibility of different contributions for vowels and consonants in early word learning.     

It's what's on the outside that matters: an advantage for external features in children's word recognition

The relative importance of internal and external letter features of words in children's developing reading was investigated to clarify further the nature of early featural analysis. In Experiment 1, 72 6-, 8-, and 10-year-olds read aloud words displayed as wholes, external features only (central features missing, thereby preserving word shape information), or internal features only (central features preserved). There was an improvement in the processing of external features compared with internal features as reading experience increased. Experiment 2 examined the processing of the internal and external features of words employing a forward priming paradigm with 60 8-, 10-, and 12-year-olds. Reaction times to internal feature primes were equivalent to a nonprime blank condition, whereas responses to external feature primes were faster than those to the other two prime types. This advantage for the external features of words is discussed in terms of an early and enduring role for processing the external visual features in words during reading development.     

Comparison of hemispheric activation during mental word and rhyme generation using transcranial Doppler sonography

The Wada test is at present the method of choice for preoperative assessment of patients who require surgery close to cortical language areas. It is, however, an invasive test with an attached morbidity risk. By now, an alternative to the Wada test is to combine a lexical word generation paradigm with non-invasive imaging techniques. However, results of this approach are still not in complete agreement with the findings of the Wada test (r = .92; Knecht, Deppe, Ebner et al., 1998). We attempted to obtain a more distinct language lateralization with the development of a phonological rhyme generation paradigm based on pseudoword stimuli. To examine the predictive value of both paradigms we performed simultaneous bilateral functional transcranial Doppler ultrasonography on 19 right-handed male native German subjects. The rhyme generation condition produced a significantly stronger lateralization to the supposed hemisphere of language dominance than the classical word generation condition. The observed differences suggest that the rhyme generation paradigm is more robust in detecting hemispheric language dominance than other neuropsychological paradigms and might be most valuable for preoperative assessment of cortical language areas.     

Orthographic neighbors and visual word recognition

Two lexical decision experiments, using words that were selected and closely matched on several criteria associated with lexical access, provide evidence of facilitatory effects of orthographic neighborhood size and no significant evidence of inhibitory effects of orthographic neighborhood frequency on lexical access. The words used in Experiment 1 had few neighbors that were higher in frequency. In Experiment 2, the words employed had several neighbors that were higher in frequency. Both experiments showed that words possessing few neighbors evoked slower responses than those possessing many neighbors. Also, in both experiments, neighborhood size effects occurred even though words from large neighborhoods had more potentially interfering higher-frequency neighbors than words from small neighborhoods.     

Time course of frequency effects in spoken-word recognition: evidence from eye movements

In two experiments, eye movements were monitored as participants followed spoken instructions to click on and move pictures with a computer mouse. In Experiment 1, a referent picture (e.g., the picture of a bench) was presented along with three pictures, two of which had names that shared the same initial phonemes as the name of the referent (e.g., bed and bell). Participants were more likely to fixate the picture with the higher frequency name (bed) than the picture with the lower frequency name (bell). In Experiment 2, referent pictures were presented with three unrelated distractors. Fixation latencies to referents with high-frequency names were shorter than those to referents with low-frequency names. The proportion of fixations to the referents and distractors were analyzed in 33-ms time slices to provide fine-grained information about the time course of frequency effects. These analyses established that frequency affects the earliest moments of lexical access and rule out a late-acting, decision-bias locus for frequency. Simulations using models in which frequency operates on resting-activation levels, on connection strengths, and as a postactivation decision bias provided further constraints on the locus of frequency effects.     

The semantic origins of word order

Where do the different sentence orders in the languages of the world come from? Recently, it has been suggested that there is a basic sentence order, SOV (Subject–Object–Verb), which was the starting point for other sentence orders. Backup for this claim was found in newly emerging languages, as well as in experiments where people are asked to convey simple meanings in improvised gesture production. In both cases, researchers found that the predominant word order is SOV. Recent literature has shown that the pragmatic rule ‘Agent first’ drives the preference for S initial word order, but this rule does not decide between SOV and SVO. This paper presents experimental evidence for grounding the word order that emerges in gesture production in semantic properties of the message to be conveyed. We focus on the role of the verb, and argue that the preference for SOV word order reported in earlier experiments is due to the use of extensional verbs (e.g. throw). With intensional verbs like think, the object is dependent on the agent’s thought, and our experiment confirms that such verbs lead to a preference for SVO instead. We conclude that the meaning of the verb plays a crucial role in the sequencing of utterances in emerging language systems. This finding is relevant for the debate on language evolution, because it suggests that semantics underlies the early formation of syntactic rules.     

The “Deliberative Digital Divide:” Opinion Leadership and Integrative Complexity in the U.S. Political Blogosphere

This study examined the association between political ideology and linguistic indicators of integrative complexity and opinion leadership in U.S. political blog posts (N = 519). Using Linguistic Inquiry and Word Count (LIWC) text analysis, we found that the posts of conservative bloggers were more integratively simple than those of liberal bloggers. Furthermore, in support of a proposed opinion leadership model of integrative complexity, the relationship between ideology and integrative complexity was mediated by psychological distancing (an indicator of a hierarchical communication style). These findings demonstrate an ideological divide in the extent to which the blogosphere reflects deliberative democratic ideals.