Religiosity and treatment response to antidepressant medication: a prospective multi-site clinical trial

The present study examined the relationship between religiosity/spirituality and treatment response to antidepressant medication (citalopram). One-hundred and forty-eight Caucasian and African-American adults with uncomplicated major depression were treated with citalopram (20–60?mg/day) over an eight-week period in a prospective multi-site clinical trial. Treatment response was assessed weekly with the Hamilton Rating Scale for Depression. Religiosity (i.e., religious behaviours) and spirituality (i.e., spiritual well-being) were assessed at week 3. No significant associations between spirituality and treatment response were found; however, there was a strong curvilinear relationship between religiosity and treatment response. Compared to lower or higher levels of religiosity, a moderate level of religiosity was significantly associated with a higher likelihood of remission and greater reduction in severity of depression. This association was independent of social support, ethnicity, gender, education, and baseline depression severity. A moderate amount of religiosity appears to be independently associated with an enhanced treatment response to citalopram.     

Intersensory effects in the psychological refractory period

Two experiments examined reaction time (RT) to each of two stimulus events separated by short interstimulus intervals (1SI). The essential contrast was RT to the second visual signal, RT₂, in auditory-visual (A-V) vs visual-visual (V-V) sequences. With response, certain pairings in Experiment 1, an effect apparently demonstrating a single-channel process (Welford, 1952), was noted. RT₂ was generally faster for A-V as opposed to V-V sequences especially when Ss were uncertain as to the sequence that would occur. At 0-msec ISI, the RT₂ difference between sequences approached the RT! difference. More rapid RT₂ to A-V sequences was also observed with go vs no-go pairings in Experiment 2 when the initial event was a go signal. However, the RT difference disappeared upon error correction, making the RT₂ sequence difference of questionable relevance to the hypothetical single-channel process. RT₂ was more rapid following a null no-go signal when the no-go signal was contrasted with a visual as opposed to auditory go signal. The latter effect was independent of error and is consistent with channel-switching theory (Kristofferson, 1967).     

Set and temporal integration

An experiment was conducted to explore the temporal structure of set formation in a complex reaction time (RT) task. On each trial an instruction [I-event] was given telling Ss whether identity of color or form on a separately presented alternative display (A-event) was the dimension relevant on that trial. The A-event consisted of a pattern of four colored forms. The two forms on one side were matched for color and on the other side for form. S’s task was to depress one of two keys. The correct key was homolateral to the matched relevant dimension. The basic independent variable was the time interval separating the I- and A-events (ISI). At short ISIs, RT wasa linear function oflSI with slope equal to -0.5. RT was independent of the order in which the events occurred at short ISIs, although at longer ISIs (3 sec) RT was longer when the A-event followed the I-event. Also, RT was shorter at short ISIs when color was the relevant dimension rather than form. although this difference disappearedat longer ISIs. The results were discussed in relation to information processing models and previous research dealing with partialadvance information.     

Effects of time and event uncertainty upon sequential information processing

Two experiments were conducted to investigate the psychological refractory period (PRP), a delay induced into the second of two reaction times (RT) when the interstimulus interval (ISI) is short. In Experiment1, time and event uncertainty were factorially varied by providing or not providing S with foreknowledge of the ISI and the order in which the two events would occur, respectively. ISIs of0, 50, 100, 200, and400 msec were used. Time and event uncertainty produced independent degradation of both RTs. Also, the second RT (RT ₂ ) was delayed at50 msec ISI when both time and event certainty were present. Experiment 2 attempted to replicate this latter finding using ISIs of0, 25, 50, 75, and100 msec. Delays in RT ₂ were found for the middle three values of ISI. These results were interpreted as supporting a modified single channel theory of the PRP.     

An analysis of U-shaped metacontrast

Using a brightness-discrimination task similar to that employed by Bernstein, Proctor, Proctor, and Schurman (1973), masking functions were obtained in two experiments. In Experiment I, test stimulus (TS) and mask stimulus (MS) energies were held constant but luminance and duration were varied reciprocally. The obtained masking functions, plotted as a function of stimulus onset asynchrony (SOA), were of an essentially identical U shape. This suggests that (a) SOA is a more suitable measure of delay than interstimulus interval, and (b) Bloch’s law holds for the requisite discrimination. In Experiment II, TS luminance and MS luminance were varied independently. This was to see whether the MS served as a frame of reference at short SOA, as suggested previously (Bernstein et al, 1973). The results were that this was, in fact, the case and that the transition from comparative to absolute judgment strategies as SOA increases is a major contributor to U-shaped masking functions.