Debra Titone

Human relational memory requires time and sleep

Relational memory, the flexible ability to generalize across existing stores of information, is a fundamental property of human cognition. Little is known, however, about how and when this inferential knowledge emerges. Here, we test the hypothesis that human relational memory develops during offline time periods. Fifty-six participants initially learned five “premise pairs” (A>B, B>C, C>D, D>E, and E>F). Unknown to subjects, the pairs contained an embedded hierarchy (A>B>C>D>E>F). Following an offline delay of either 20 min, 12 hr (wake or sleep), or 24 hr, knowledge of the hierarchy was tested by examining inferential judgments for novel “inference pairs” (B>D, C>E, and B>E). Despite all groups achieving near-identical premise pair retention after the offline delay (all groups, >85%; the building blocks of the hierarchy), a striking dissociation was evident in the ability to make relational inference judgments: the 20-min group showed no evidence of inferential ability (52%), whereas the 12- and 24-hr groups displayed highly significant relational memory developments (inference ability of both groups, >75%; P < 0.001). Moreover, if the 12-hr period contained sleep, an additional boost to relational memory was seen for the most distant inferential judgment (the B>E pair; sleep = 93%, wake = 69%, P = 0.03). Interestingly, despite this increase in performance, the sleep benefit was not associated with an increase in subjective confidence for these judgments. Together, these findings demonstrate that human relational memory develops during offline time delays. Furthermore, sleep appears to preferentially facilitate this process by enhancing hierarchical memory binding, thereby allowing superior performance for the more distant inferential judgments, a benefit that may operate below the level of conscious awareness.

Bilingual lexical access in context: Evidence from eye movements during reading.

Current models of bilingualism (e.g., BIA+) posit that lexical access during reading is not language selective. However, much of this research is based on the comprehension of words in isolation. The authors investigated whether nonselective access occurs for words embedded in biased sentence contexts (e.g., A. I. Schwartz & J. F. Kroll, 2006). Eye movements were recorded as French-English bilinguals read English sentences containing cognates (e.g., piano), interlingual homographs (e.g., coin, meaning corner in French), or matched control words. Sentences provided a low or high semantic constraint for target-language meanings. Both early-stage comprehension measures (e.g., first fixation duration, gaze duration, and skipping) and late-stage comprehension measures (e.g., go-past time and total reading time) showed significant cognate facilitation and interlingual homograph interference for low-constraint sentences. For high-constraint sentences, however, only early-stage comprehension measures were consistent with nonselective access. There was no evidence of cognate facilitation or interlingual homograph interference for late-stage comprehension measures. Thus, nonselective bilingual lexical access at early stages of comprehension is rapidly resolved in semantically biased contexts at later stages of comprehension.

Moving toward a neuroplasticity view of bilingualism, executive control, and aging

Normal aging is an inevitable race between increasing knowledge and decreasing cognitive capacity. Crucial to understanding and promoting successful aging is determining which of these factors dominates for particular neurocognitive functions. Here, we focus on the human capacity for language, for which healthy older adults are simultaneously advantaged and disadvantaged. In recent years, a more hopeful view of cognitive aging has emerged from work suggesting that age-related declines in executive control functions are buffered by life-long bilingualism. In this paper, we selectively review what is currently known and unknown about bilingualism, executive control, and aging. Our ultimate goal is to advance the views that these issues should be reframed as a specific instance of neuroplasticity more generally and, in particular, that researchers should embrace the individual variability among bilinguals by adopting experimental and statistical approaches that respect the complexity of the questions addressed. In what follows, we set out the theoretical assumptions and empirical support of the bilingual advantages perspective, review what we know about language, cognitive control, and aging generally, and then highlight several of the relatively few studies that have investigated bilingual language processing in older adults, either on their own or in comparison with monolingual older adults. We conclude with several recommendations for how the field ought to proceed to achieve a more multifactorial view of bilingualism that emphasizes the notion of neuroplasticity over that of simple bilingual versus monolingual group comparisons.

Idiom processing in schizophrenia: Literal implausibility saves the day for idiom priming

Schizophrenia patients have difficulty processing nonliteral forms of discourse such as idiomatic expressions. We hypothesized that schizophrenia patients would show impaired idiom processing for literally plausible idioms (e.g., kick the bucket) but not for literally implausible idioms (e.g., be on cloud nine). Thirty-two patients and 36 controls listened to sentences containing literally plausible and implausible idioms and made lexical decisions about idiom-related or literal-related targets. Schizophrenia patients showed reduced priming for literally plausible idioms but intact priming for literally implausible idioms compared with controls. Both groups showed evidence of literal word priming. These results are consistent with the notion that schizophrenia patients make normal use of context under conditions that minimize the need for controlled processing.

The multidetermined nature of idiom processing

Models of idiom comprehension differ in their predictions concerning compositionality: Some claim that idiomatic meaning is the result of compositional analysis initiated at the earliest stages of comprehension, whereas others claim that compositional analysis occurs only at late stages, subsequent to direct retrieval—especially for idioms that are highly familiar. We evaluated these alternatives in four experiments by using a variety of online and offline comprehension measures. In Experiment 1, we analyzed the normative characteristics of 219 idioms with respect to these predictions. Dimensions of interest included several measures of decomposability, familiarity, and word frequency of the idioms’ verbs and nouns. In Experiments 2 through 4, we determined how these dimensions relate to several online measures of idiom comprehension. High familiarity was associated with good comprehension across all experiments; however, facilitative effects of decomposability were found only for tasks that required an overt semantic judgment. Word frequency, but not semantic decomposability of the idiom-initial verb, was associated with comprehension for some measures. These data support a model of idiom comprehension, according to which figurative meaning arises from the time-dependent availability of multiple linguistic constraints, and in which decomposability plays a limited role in the earliest stages of idiom comprehension. Normative data for 210 of the idiomatic phrases may be downloaded from the Psychonomic Society Web archive at www.psychonomic.org/archive/.

Bilingual Lexical Access during L1 Sentence Reading: The Effects of L2 Knowledge, Semantic Constraint, and L1-L2 Intermixing.

Libben and Titone (2009) recently observed that cognate facilitation and interlingual homograph interference were attenuated by increased semantic constraint during bilingual second language (L2) reading, using eye movement measures. We now investigate whether cross-language activation also occurs during first language (L1) reading as a function of age of L2 acquisition and task demands (i.e., inclusion of L2 sentences). In Experiment 1, participants read high and low constraint English (L1) sentences containing interlingual homographs, cognates, or control words. In Experiment 2, we included French (L2) filler sentences to increase salience of the L2 during L1 reading. The results suggest that bilinguals reading in their L1 show nonselective activation to the extent that they acquired their L2 early in life. Similar to our previous work on L2 reading, high contextual constraint attenuated cross-language activation for cognates. The inclusion of French filler items promoted greater cross-language activation, especially for late stage reading measures. Thus, L1 bilingual reading is modulated by L2 knowledge, semantic constraint, and task demands.

Making Sense of Word Senses: The Comprehension of Polysemy Depends on Sense Overlap.

Studies of polysemy are few in number and are contradictory. Some have found differences between polysemy and homonymy (L. Frazier & K. Rayner, 1990), and others have found similarities (D. K. Klein & G. Murphy, 2001). The authors investigated this issue using the methods of D. K. Klein and G. Murphy (2001), in whose study participants judged whether ambiguous words embedded in word pairs (e.g., tasty chicken) made sense as a function of a cooperating, conflicting, or neutral context. The ambiguous words were independently rated as having low, moderate, or highly overlapping senses to approximate a continuum from homonymy to metonymic polysemy. The effects of meaning dominance were examined. Words with highly overlapping meanings (e.g., metonymy) showed reduced effects of context and dominance compared with words with moderately or low overlapping meanings (e.g., metaphorical polysemy and homonymy). These results suggest that the comprehension of ambiguous words is mediated by the semantic overlap of alternative senses/meanings.

The misattribution of salience in delusional patients with schizophrenia

INTRODUCTION Delusions may arise from abnormalities in emotional perception. In this study, we tested the hypothesis that delusional schizophrenia patients are more likely than non-delusional schizophrenia patients and healthy participants to assign affective meanings to neutral stimuli. METHODS Unpleasant, pleasant, and neutral words were randomly presented to three subject groups--patients with schizophrenia with prominent delusions, patients with schizophrenia without delusions, and healthy participants. Participants performed three tasks: one in which they decided whether a letter string was a word or a non-word (lexical decision) and two affective classification tasks in which they judged whether words were 1) neutral or unpleasant, or 2) neutral or pleasant. RESULTS While there were no significant between-group differences in lexical decision performance, patients with delusions showed selective performance deficits in both affective classification tasks. First, delusional patients were significantly more likely than non-delusional patients and healthy participants to classify words as unpleasant. Second, delusional patients took significantly longer than both other groups to correctly classify neutral words in both affective classification tasks. CONCLUSIONS Taken together, these findings suggest that delusions are associated with the explicit misattribution of salience to neutral stimuli.

Second-Language Experience Modulates First- and Second-Language Word Frequency Effects: Evidence from Eye Movement Measures of Natural Paragraph Reading

We used eye movement measures of first-language (L1) and second-language (L2) paragraph reading to investigate whether the degree of current L2 exposure modulates the relative size of L1 and L2 frequency effects (FEs). The results showed that bilinguals displayed larger L2 than L1 FEs during both early- and late-stage eye movement measures, which are taken to reflect initial lexical access and postlexical access, respectively. Moreover, the magnitude of L2 FEs was inversely related to current L2 exposure, such that lower levels of L2 exposure led to larger L2 FEs. In contrast, during early-stage reading measures, bilinguals with higher levels of current L2 exposure showed larger L1 FEs than did bilinguals with lower levels of L2 exposure, suggesting that increased L2 experience modifies the earliest stages of L1 lexical access. Taken together, the findings are consistent with implicit learning accounts (e.g., Monsell, 1991), the weaker links hypothesis (Gollan, Montoya, Cera, Sandoval, Journal of Memory and Language, 58:787–814, 2008), and current bilingual visual word recognition models (e.g., the bilingual interactive activation model plus [BIA+]; Dijkstra & van Heuven, Bilingualism: Language and Cognition, 5:175–197, 2002). Thus, amount of current L2 exposure is a key determinant of FEs and, thus, lexical activation, in both the L1 and L2.

The influence of prosodic structure on the interpretation of temporary syntactic ambiguity by young and elderly listeners.

The contribution of prosody to the interpretation of temporary syntactic ambiguity was examined for young and elderly listeners using a sentence-completion task. Temporary syntactic ambiguity refers to cases where it may be temporarily unclear whether a syntactic clause boundary has or has not been reached based on what has been heard in the sentence to that point. Results suggest that both young and elderly adults use a computationally less demanding late-closure parsing strategy whenever possible, but that sentence prosody can override this tendency when an alternative closure position is clearly signaled. Although subtle differences appeared in regard to sentence completion strategies and latencies to completion, results suggest that efficient resolution of syntactic boundary uncertainty and effective use of sentence prosody are two features of language comprehension that remain well-preserved in normal aging.