"slightly pleasant" is a correct phrase and can be used in written English.
It indicates that something is somewhat enjoyable or agreeable, but not to a great extent. Example: The weather was slightly pleasant, with a soft breeze and a hint of sunshine.
Humans have the dual capacity to assign a slightly pleasant valence to neutral stimuli (the positivity offset) to encourage approach behaviors, as well as to assign a higher negative valence to unpleasant images relative to the positive valence to equally arousing and extreme pleasant images (the negativity bias) to facilitate defensive strategies.
The slightly pleasant summer of "Get Lucky" turned into the creepy totalitarianism of "Blurred Lines", and now you can't even go for a pint without catching a glimpse on the pub TV of Bruno Mars crotch-sliding across the greased bonnets of a Corvette.
Inspection of the mean ratings shows that the autism spectrum condition group judged the unpleasantness of the low pain stimulation to be close to zero, while the controls rated the low pain as slightly pleasant (Table 4).
In accordance with the nonzero intensities at 0% concentration, the pleasantness scores of valeric acid and butanoic acid at this concentration were not neutral, but in fact slightly pleasant.
Conversely, benign images were rated as slightly pleasant on average (mean ratings were midway between "neutral" and "pleasant") and these ratings were lower (i.e., more pleasant) than for verbal descriptions of the same object.
The descriptors for pleasantness/unpleasantness were 0, extremely pleasant; 1, very pleasant; 2, moderately pleasant; 3, slightly pleasant; 4, neither pleasant nor unpleasant; 5, slightly unpleasant; 6, moderately unpleasant; 7, very unpleasant; and 8, extremely unpleasant.
For example, for the scale "pleasant/unpleasant," each category corresponded to the degree of pleasantness impression as follows: 1-extremely pleasant, 2-fairly pleasant, 3-slightly pleasant, 4-moderate, 5-slightly unpleasant, 6-fairly unpleasant, and 7-extremely unpleasant.
Answering options were very pleasant (4), pleasant (3), somewhat pleasant (2), not pleasant (1).
Another surprise, but perhaps a slightly more pleasant one, is the inclusion of Dexter in the International category.
First, the leaf wrapping will have some substance and a slightly bitter, pleasant taste of its own.
But there were also a number of activities that produced very different reactions from the two sexes — and one of them really stands out: Men apparently enjoy being with their parents, while women find time with their mom and dad to be slightly less pleasant than doing laundry.
