Deborah L. Delanoy
A vast array of parapsychological work has been conducted over the past century. Summarising and describing parts of this work have been greatly aided by recent meta-analyses of some areas of parapsychological research. Meta-analysis of some groups of experimental studies has provided a way of assessing the overall significance of a large number of studies (i.e. examining the likelihood that the outcomes are due to chance), arriving at an estimate of the magnitude of the effect being examined (i.e. determining the effect size of an experimental outcome), and has aided in uncovering trends and patterns contained within the databases. (See Chapter 2 for a discussion of meta-analytic procedures, including the procedure's strengths and weaknesses.)
Below, the findings of meta-analyses of nine parapsychological databases are discussed. All of the key meta-analyses have been fully published in refereed journals. They represent a variety of different experimental procedures. The databases include extrasensory perception (ESP) and psychokinesis (PK) studies, as well as some of the research relating psi performance to personality. Collectively these studies represent a sizeable proportion of the parapsychological experimental literature conducted over the last sixty years.
The ganzfeld technique aims to help percipients obtain ESP impressions. The ganzfeld may be psi-conducive by helping a participant to better direct their attention to their internal processes and thereby become more aware of subtle ESP impressions which might otherwise be drowned-out by our normal, more noticeable, sensory input (Honorton 1977). Ganzfeld stimulation can bring on a mildly altered state of consciousness, often thought to be similar in experience to the hypnagogic state. While receiving this stimulus, the percipient says out loud all their mental experiences (these are referred to as 'mentations'), with the goal of receiving impressions of a sensorially isolated and remotely located target picture or short video clip.