Tree Inference: Response Time and Other Measures in a Binary Multinomial Processing Tree, Representation and Uniqueness of Parameters

A Multinomial Processing Tree (MPT) is a directed tree with a probability associated with each arc and partitioned terminal vertices. We consider an additional parameter for each arc, a measure such as time. Each vertex represents a process. An arc descending from a vertex represents selection of a process outcome. A source vertex represents processing beginning with stimulus presentation and a terminal vertex represents a response. An experimental factor selectively influences a vertex if changing the factor level changes parameter values on arcs descending from that vertex and no others. Earlier work shows that if each of two factors selectively influences a different vertex in an arbitrary MPT it is equivalent to one of two simple MPTs. Which applies depends on whether the two selectively influenced vertices are ordered by the factors or not. A special case, the Standard Binary Tree for Ordered Processes, arises if the vertices are ordered and the factor selectively influencing the first vertex changes parameter values on only two arcs. We derive necessary and sufficient conditions, testable by bootstrapping, for this case. Parameter values are not unique. We give admissible transformations for them. We calculate degrees of freedom needed for goodness of fit tests.

Nighttime sleep benefits the prospective component of prospective memory

Studies suggest that sleep benefits event-based prospective memory, which involves carrying out intentions when particular events occur. Prospective memory has a prospective component (remembering that one has an intention), and a retrospective component (remembering when to carry it out). As effects of sleep on retrospective memory are well established, the effect of sleep on prospective memory may thus be due exclusively to an effect of sleep on its retrospective component. Therefore, the authors investigated whether nighttime sleep improves the prospective component of prospective memory, or a retrospective component, or both. In a first session, participants performed an event-based prospective-memory task (that was embedded in an ongoing task) 3 minutes after forming an intention and, in a second session, 12 hours after forming an intention. The sessions were separated by either nighttime sleep or daytime wakefulness. The authors disentangled prospective-memory performance into its retrospective and prospective components via multinomial processing tree modeling. There was no effect of sleep on the retrospective component, which may have been due to a time-of-day effect. The prospective component, which is the component unique to prospective memory, declined less strongly after a retention interval filled with sleep as compared with a retention interval filled with wakefulness. A hybrid interaction suggested that refreshed attention after sleep may account for this effect, but did not support the consolidation of the association between the intention and its appropriate context as a mechanism driving the effect.

A Multinomial Processing Tree Model of RC Attachment

In the field of sentence processing, speakers’ preferred interpretation of ambiguous sentences is often determined using a variant of a discrete choice task, in which participants are asked to indicate their preferred meaning of an ambiguous sentence. We discuss participants’ degree of attentiveness as a potential source of bias and variability in such tasks.We show that it may distort the estimates of the preference of a particular interpretation obtained in such experiments and may thus complicate the interpretation of the results as well as the comparison of the results of several experiments. We propose an analysis method based on multinomial processing tree models (Batchelder and Riefer, 1999) which can correct for this bias and allows for a separation of parameters of theoretical importance from nuisance parameters. We test two variants of the MPT-based model on experimental data from English and Turkish and demonstrate that our method can provide deeper insight into the processes underlying participants’ answering behavior and their interpretation preferences than analyses based on raw percentages.

Second-guessing of Spinoza: Psychophysiological and behavioral evidence that believing is default during proposition comprehension

The belief-default model contends that believing is inexorable during comprehension, and falsification is a subsequent, secondary process. By contrast, the Cartesian belief-fixation model argues that naïve propositions may be mentally represented without a truth or falsity stance. In the present research, data from four studies help adjudicate belief-fixation models, favoring the belief-default model: Studies 1-3 show that newly represented propositions are initially believed as the consequences of the truth from a naïve represented proposition will automatically activate contradictory mental information even when this processing impairs task performance (a “false” false alarm belief bias). Naïve propositions cannot be “merely” represented (without a truth stance) during comprehension. Studies 3 and 4 reveal unique electrodermal activity signals corresponding to propositions considered to be either true or false. We argue that the observed autonomic reactivity constitutes the source of two different epistemic emotions associated with the perceived outcomes of a memory search (i.e., “aha” and wrongness, respectively). To account for the psychophysiological results, we hypothesize that the epistemic emotion of familiarity is substantiated by an “aha” emotion which signals the recovery of represented propositions considered true during mnemonic processing. In addition, we show that anti-belief-default conclusions from recent investigations using multinomial processing tree modeling are tenuous as they depend on the type of false information paradigm employed. In sum, the data support the belief-default model and indicate a novel psychophysiological method to distinguish “believed” memory retrieval products from “guessed” responses derived via metacognitive strategies during veridical identification.